Securing data using key agreement

Abstract

To provide methods and systems for securing customer data in a multi-tenant database environment.SOLUTION: A key identifier received from a security server may be stored by an application server. The key identifier may be associated with a private key that is accessible by the security server and not accessible by the application server. A request to derive a symmetric key may be transmitted from the application server to the security server, the request including a public key generated by the application server, a salt value, and the key identifier. The symmetric key may then be derived based on the transmitted public key and the private key using a key derivation function. The application server may then receive and store the symmetric key in an in-memory cache, and be used to securely encrypt data received by the application server from client devices.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] A portion of the disclosure of this patent document contains material that is subject to copyright protection. As the patent document or patent disclosure appears in the U.S. Patent and Trademark Office patent files or records, the copyright owner has no objection to its facsimile reproduction, but otherwise reserves all copyright whatsoever. Related Art

[0002] The present disclosure relates generally to data processing, and more particularly to encrypting and decrypting data. [Background technology]

[0003] The subject matter discussed in the Background Art section should not be assumed to be prior art merely as a result of its mention in the Background Art section. Similarly, it should not be assumed that the problems mentioned in or associated with the subject matter in the Background Art section have been previously recognized in the prior art. The subject matter in the Background Art section may merely represent different approaches and may itself be inventions.

[0004] The following detailed description is provided with reference to the disclosed technology. Preferred implementations are described to illustrate the disclosed technology, not to limit the scope defined by the claims. Those skilled in the art will recognize various equivalent variations to this description.

[0005] Existing approaches for securing data (e.g., customer data) stored in storage areas (e.g., databases, data stores, etc.) may be based on asymmetric or symmetric cryptography. Asymmetric cryptography uses a key pair: a public key and a private key. Customer data can be encrypted using the public key and decrypted using the corresponding private key. Typically, encrypting data using the public key of an asymmetric key pair is very slow. Instead, encrypting data using a symmetric key is an acceptable practice. The symmetric key is itself encrypted with the public key, thereby solving the performance issues of asymmetric key cryptography. Summary of the Invention

[0006] A method and system for securing customer data in a multi-tenant database environment are described. A key identifier received from a security server via a network connection may be stored by an application server. The key identifier may be associated with a private key, where the private key is accessible by the security server and inaccessible by the application server. The application server may also communicate with multiple client devices via the network. A request to derive a symmetric key may be sent from the application server to the security server. The request may be sent after the application server stores the key identifier and may include a public key, a salt value, and the key identifier generated by the application server. The symmetric key is then derived by the security server using a key derivation function based on the sent public and private keys and sent to the application server. The application server may then store the symmetric key in an in-memory cache of the application server and use it to encrypt data received from one of the multiple client devices.

[0007] Other aspects and advantages of the present invention may be seen upon review of the following drawings, detailed description and claims. [Brief explanation of the drawings]

[0008] The included drawings are for illustrative purposes and serve only to provide examples of possible structures and process steps for the disclosed technology. These drawings in no way limit any changes in form and detail that may be made to the embodiments by those skilled in the art without departing from the spirit and scope of the present disclosure.

[0009] [Figure 1] 1 shows a diagram of an exemplary computing system that may be used in some embodiments of the present invention.

[0010] [Figure 2] 1 shows a diagram of an exemplary network environment that may be used in some embodiments of the present invention.

[0011] [Figure 3] 1 illustrates an exemplary relationship between a symmetric key and a customer, according to some embodiments.

[0012] [Figure 4] 1 illustrates a flowchart of an exemplary process performed in accordance with some embodiments for encrypting customer data using a symmetric key generated using key agreement.

[0013] [Figure 5] 1 illustrates a flowchart of an exemplary process for generating a request for a symmetric key generated using a key agreement, according to some embodiments.

[0014] [Figure 6] 1 illustrates an exemplary data structure listing different symmetric keys assigned to different tenants in a multi-tenant environment, according to various embodiments.

[0015] [Figure 7] 1 illustrates an exemplary data structure listing key identifiers with corresponding private keys, according to various embodiments.

[0016] [Figure 8] 1 illustrates a flowchart of an exemplary process for generating symmetric keys generated using key agreement, performed in accordance with some embodiments.

[0017] [Figure 9] 1 illustrates a flowchart of an exemplary process for performing key rotation on an application server, according to various embodiments.

[0018] [Figure 10] 1 illustrates an exemplary data structure for storing rotated symmetric keys for customers in a multi-tenant environment, according to various embodiments.

[0019] [Figure 11] 1 illustrates an exemplary data structure representing the destruction of a symmetric key, according to various embodiments.

[0020] [Figure 12A] 8 shows a system diagram 800 illustrating architectural components of an applicable environment, according to some embodiments.

[0021] [Figure 12B] FIG. 1 shows a system diagram further illustrating architectural components of an applicable environment, according to some embodiments.

[0022] [Figure 13] FIG. 1 shows a system diagram illustrating the architecture of a multi-tenant database environment, according to some embodiments.

[0023] [Figure 14] FIG. 1 shows a system diagram further illustrating the architecture of a multi-tenant database environment, according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0024] Applications of the systems and methods according to one or more embodiments are described in this section. These examples are provided merely to add context to and aid in understanding of the present disclosure. Thus, it will be apparent to one of ordinary skill in the art that the techniques described herein may be practiced without some or all of these specific details. In other instances, well-known process steps have not been described in detail to avoid unnecessarily obscuring the present disclosure. Other applications are possible, and as a result, the following examples should not be taken as definitive or limiting either in scope or setting.

[0025] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof and which show, by way of illustration, specific embodiments. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, but these examples are not limiting, and consequently other embodiments may be used and changes may be made without departing from the spirit and scope of the disclosure.

[0026] As used herein, the term "multitenant database system" refers to a system in which various elements of the database system's hardware and software may be shared by one or more customers. For example, a given application server may process requests for multiple customers simultaneously, and a given database table may store rows for a potentially larger number of customers.

[0027] The described subject matter may be implemented in the context of any computer-implemented system, such as a software-based system, a database system, a multi-tenant environment, etc. Additionally, the described subject matter may be implemented in connection with two or more separate and distinct computer-implemented systems that cooperate and communicate with each other. One or more embodiments may be implemented in numerous ways, including as a process, an apparatus, a system, a device, a method, a computer-readable medium, such as a computer-readable storage medium, that includes computer-readable instructions or computer program code, a computer program product that includes a computer-usable medium with computer-readable program code embodied therein, etc.

[0028] In general, a multitenant database environment may include multiple databases configured to store data associated with an organization or customer. The data (also referred to as customer data) may be unencrypted when stored by the customer. The customer data may be encrypted at rest using asymmetric or symmetric encryption. Encrypted customer data protects the data from being accessed by unauthorized users. While it may be important to encrypt customer data, it may be desirable to secure the decryption key (private or symmetric). The decryption key may be stored in a storage area accessible only to specific authorized personnel (e.g., a database administrator). When a customer wishes to retrieve the customer data, the encrypted customer data may be decrypted using the decryption key. The decrypted customer data may then be transmitted to the customer. The encrypted customer data may be stored in any storage area associated with the multitenant database environment, including cloud-based storage areas, non-cloud-based storage areas, or other forms of storage implementation.

[0029] One technique for protecting decryption keys is to use a Hardware Security Module (HSM). HSMs provide on-board secure key generation and on-board key storage management. HSMs may be used to generate asymmetric or symmetric key pairs. The HSM may keep the private key in its storage so that it cannot be extracted by an outside party. A password may be required to use an HSM installed in a system. The HSM may be a Universal Serial Bus (USB) device connected through a USB port, a card device installed through the system board, or a network-attached device.

[0030] Traditional systems for securing customer data may use key wrapping to generate symmetric keys that are later used to encrypt the customer data. Other systems may utilize Rivest-Shamir-Adleman (RSA) encryption to communicate messages between client systems and application servers. Such approaches have several drawbacks. First, the private key must remain locked to the application server, meaning there are multiple potential areas where security can be compromised (the application server and the HSM server). Also, using traditional approaches, symmetric key derivation can involve time-consuming and computationally expensive processes, such as password-based key wrapping. Given the significant resource demands of the key derivation process, HSMs are often required to cache all key fragments used for encryption. In multi-tenant environments, this can create a significant security risk, as unauthorized access to an HSM could result in a malicious user gaining access to the symmetric keys of multiple entities. Furthermore, it has been speculated that quantum computing could compromise RSA encryption in the future, making customer data encrypted using RSA keys vulnerable.

[0031] The disclosed embodiments may relate to encrypting and decrypting or securing customer data in a computer-implemented system. The described subject matter may be implemented in the context of any computer-implemented system, such as a software-based system, a database system, a multi-tenant environment, etc. Additionally, the described subject matter may be implemented in connection with two or more separate and distinct computer-implemented systems that cooperate and communicate with each other. One or more implementations may be implemented in numerous ways, including as a process, an apparatus, a system, a device, a method, a computer-readable medium, such as a computer-readable storage medium, including computer-readable instructions or computer program code, a computer program product, including a computer-usable medium having computer-readable program code embodied therein, etc. Computer Systems

[0032] 1 is a diagram of an exemplary computing system that may be used in some embodiments of the present invention. The computing system 102 may be used by a customer or organization to transmit customer data to be stored in a storage area associated with a multi-tenant database environment. For example, the multi-tenant database environment may be associated with services offered by Salesforce.com®. The computing system 102 may also be used to retrieve customer data from the storage area.

[0033] Computing system 102 is merely one example of a suitable computing system, such as a mobile computing system, and is not intended to suggest any limitation as to the scope of use or functionality of the design. Furthermore, computing system 102 should not be interpreted as having any dependency or requirement relating to any one or combination of the illustrated components. The design operates with numerous other general-purpose or special-purpose computing systems. Examples of well-known computing systems, environments, and / or configurations that may be suitable for use with the design include, but are not limited to, personal computers, server computers, handheld or laptop devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics devices, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like. For example, computing system 102 may be implemented as a mobile computing system, such as one configured to operate with an operating system (e.g., iOS) developed by Apple Inc. of Cupertino, California, or an operating system (e.g., Android) developed by Google Inc. of Mountain View, California.

[0034] Some embodiments of the present invention may be described in the general context of computer system executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Those skilled in the art will be able to implement the descriptions and / or figures herein as computer-executable instructions, which may be embodied on any form of computing machine-readable medium, as discussed below.

[0035] Some embodiments of the invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.

[0036] 1, computing system 102 may include, but is not limited to, a processing unit 120 having one or more processing cores, a system memory 130, and a system bus 121 that couples various system components, including system memory 130, to processing unit 120. System bus 121 may be any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. By way of example and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) bus, and Peripheral Component Interconnect (PCI) bus, also known as mezzanine bus.

[0037] Computer system 102 typically includes a variety of computer-readable media. Computer-readable media can be any available media that can be accessed by computer system 102, including both volatile and nonvolatile media, removable and non-removable media. By way of example, and not limitation, computer-readable media may store information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory, or other memory technology, CD-ROM, digital versatile disks (DVDs), or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage, or other magnetic storage, or any other medium that can be used to store desired information and that can be accessed by computing system 102. Communication media typically embodies computer-readable instructions, data structures, or program modules.

[0038] System memory 130 may include computer storage media in the form of volatile and / or nonvolatile memory such as read-only memory (ROM) 131 and random access memory (RAM) 132. A basic input / output system (BIOS) 133, containing the basic routines that help to transfer information between elements within computing system 102, such as during start-up, is typically stored in ROM 131. RAM 132 typically contains data and / or program modules that are immediately accessible to and / or presently being operated on by processing unit 120. By way of example, and not limitation, FIG. 1 also illustrates operating system 134, application programs 135, other program modules 136, and program data 137.

[0039] Computing system 102 may also include other removable / non-removable, volatile / non-volatile computer storage media. By way of example only, FIG. 1 also illustrates hard disk drive 141, which reads from or writes to non-removable, non-volatile magnetic media, magnetic disk drive 151, which reads from or writes to removable, non-volatile magnetic disk 152, and optical disk drive 155, which reads from or writes to removable, non-volatile optical disk 156, such as a CD-ROM or other optical media. Other removable / non-removable, volatile / non-volatile computer storage media that may be used in the exemplary operating environment include, but are not limited to, USB drives and devices, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid-state RAM, solid-state ROM, and the like. Hard disk drive 141 is typically connected to system bus 121 through a non-removable memory interface, such as interface 140, and magnetic disk drive 151 and optical disk drive 155 are typically connected to system bus 121 by removable memory interfaces, such as interface 150.

[0040] The drives and their associated computer storage media, discussed above and illustrated in FIG. 1, provide storage of computer-readable instructions, data structures, program modules, and other data for computer system 102. In FIG. 1, for example, hard disk drive 141 is illustrated as storing operating system 144, application programs 145, other program modules 146, and program data 147. Note that these components can either be the same as or different from operating system 144, application programs 145, other program modules 136, and program data 137. Operating system 144, application programs 145, other program modules 146, and program data 147 are given different numerical identifications here to illustrate that, at a minimum, they are different copies.

[0041] A user may enter commands and information into computing system 102 through input devices such as a keyboard 162, a microphone 163, and a pointing device 161, such as a mouse, trackball, touchpad, or touch screen. Other input devices (not shown) may include a joystick, game pad, scanner, or the like. These and other input devices are often connected to processing unit 120 through a user input interface 160 coupled to system bus 121, but may also be connected by other interface and bus structures, such as a parallel port, a game port, or a universal serial bus (USB). A monitor 191 or other type of display device is also connected to system bus 121 via an interface, such as a video interface 190. In addition to a monitor, computers may also include other peripheral output devices such as speakers 197 and printer 196, which may be connected through an output peripheral interface 190.

[0042] Computer system 102 may operate in a networked environment using logical connections to one or more remote computers, such as remote computer 180. Remote computer 180 may be a personal computer, handheld device, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to computer system 102. The logical connections depicted in FIG. 1 include a local area network 171 and a wide area network 173, but may also include other networks. Such networking environments are commonplace in offices, enterprise-wide networks, intranets and the Internet.

[0043] When used in a LAN networking environment, computing system 102 may be connected to LAN 171 via network interface or adapter 170. When used in a WAN networking environment, computing system 102 typically includes a modem 172 or other means for establishing communications over WAN 173, such as the Internet. Modem 172 may be internal or external and may be connected to system bus 121 via user input interface 160 or other appropriate mechanism. In a networked environment, program modules depicted for computing system 102, or portions thereof, may be stored in remote memory storage devices. By way of example, and not limitation, FIG. 1 illustrates remote application programs 185 as residing on remote computer 180. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between computers may be used.

[0044] It should be noted that some embodiments of the present invention may be implemented on a computing system such as that described with respect to Figure 1. However, some embodiments of the present invention may also be performed on a server, a computer dedicated to message handling, a handheld device, or a distributed system in which different parts of the design of the present invention may be implemented in different parts of the distributed computing system.

[0045] Another device that may be coupled to system bus 121 is a power source, such as a battery, a direct current (DC) power source, and an alternating current (AC) adapter circuit. The DC power source may be a battery, a fuel cell, or a similar DC power source, and may need to be periodically recharged. Communications module (or modem) 172 may use the Wireless Application Protocol (WAP) to establish a wireless communication channel. Communications module 172 may implement a wireless networking standard, such as the IEEE 802.11 standard, IEEE std. 802.11-1999, published by the Institute of Electrical and Electronics Engineers (IEEE) in 1999.

[0046] Examples of mobile computing systems may be laptop computers, tablet computers, netbooks, smartphones, personal digital assistants, or other similar devices that are powered by a direct current (DC) power source that provides DC voltage to the mobile computing system and that have on-board processing power and wireless communication capabilities that must be periodically recharged, such as a fuel cell or battery, that resides solely within the mobile computing system.

[0047] 2 shows a diagram of an exemplary network environment that may be used in some embodiments of the present invention. Network environment 200 includes computing systems 205 and 212. One or more of computing systems 205 and 212 may be mobile computing systems. Computing systems 205 and 212 may be connected to network 250 via a cellular connection or a Wi-Fi router (not shown). Network 250 may be the Internet. Computing systems 205 and 212 may be coupled to one or more server computing systems 255 and 260 via network 250.

[0048] The application server 255 may communicate with multiple customer devices over a network. Each computing system 205 may be associated with a customer and may include a customer application module 208. A user may use the user computing system 205 and the user application module 208 to connect to and communicate with a server computing system 255 (also referred to as an application server 255) and log in to an application 257 (e.g., the Salesforce.com® application). A user may send customer data to or request customer data from the application server 255.

[0049] The application server 255 may be coupled to a database 270 configured to store customer data. The application server 255 may be associated with an entity (e.g., Salesforce.com®). The entity may generate a key pair for encryption. The key pair includes a public key 273 and a private key (not shown). The private key is not made publicly available and is kept secret by the entity (also called a key holder). The public key 273 may be made available to anyone by means of a digital certificate issued by a certification authority (CA). The certificate is also confirmation or verification by the CA that the public key included in the certificate belongs to the entity named in the certificate. For example, a customer can download the certificate and obtain the public key 273 to encrypt customer data sent to the application server 255. Only the entity (or the holder of the private key) can decrypt customer data encrypted using the public key 273.

[0050] The application server 255 may be coupled to a cryptographic computing system 212 configured with a cryptographic application module 214. The cryptographic application module 214 may be configured to generate public keys, private keys, symmetric keys, and one or more key fragments for dekeying, as described in FIG. 4A.

[0051] The application server 255 may be coupled to a file system 271. The file system 271 may be configured to store various cryptographic keys, including keys generated by the cryptographic computing system 212.

[0052] The application server 255 may be coupled to a security server computing system 260 (also referred to as an HSM server 260) configured with an HSM 266. The HSM 266 may be associated with an HSM public key 267 and an HSM private key 268. The HSM server 260 may include an HSM application module 265 configured to interact with the HSM 266 and perform various encryption and decryption operations. For example, the HSM application module 265 may use the HSM private key 268 to decrypt data that was previously encrypted using the corresponding HSM public key 267. A password may be required to access the HSM 266. For load balancing purposes, there may be multiple application servers 255 and multiple HSM servers 260 connected to a load balancer (not shown). Every application server 255 may need to know which HSM server 260 it can talk to at a particular time.

[0053] In some embodiments, file system 271 may be synchronized with a file system local to HSM server 260. This allows HSM server 260 to access and store data in file system 271 as if it were a local file system. In some embodiments, HSM server 260 may only respond to queries sent by application server 255. This may prevent access to data or services associated with HSM server 260 by any unauthorized user. For example, application server 255 may be required to digitally sign all requests they send to HSM server 260 using a secret they share. Use of Symmetric Keys

[0054] 3 illustrates an exemplary relationship between a symmetric key and a customer, according to some embodiments. In this example, there are two customers 315 and 325. In operation, customer 315 may send its customer data 320 to application server 255. Application server 255 then encrypts customer data 320 using a symmetric key 322 unique to customer 315 to generate encrypted customer data 324. Encrypted customer data 324 is then stored in database 270. Subsequently, when customer 315 requests its customer data, encrypted customer data 324 is retrieved from database 270 and decrypted by application server 255 using symmetric key 322, and decrypted customer data 320 is sent to customer 315.

[0055] Similarly, customer 325 may send its customer data 330 to application server 255. Application server 255 then encrypts customer data 330 using a symmetric key 332 unique to customer 325 to generate encrypted customer data 334. The encrypted customer data 334 is then stored in database 270. Thereafter, when customer 325 requests the customer data, the encrypted customer data 334 is retrieved from database 270 and decrypted by application server 255 using symmetric key 332, and the decrypted customer data 330 is sent to customer 325.

[0056] When application server 255 needs to access symmetric key 322 or 332, application server 255 may check to find out whether symmetric key 322 or 332 exists in in-memory cache 307. If symmetric key 322 or 332 exists in in-memory cache 307, it may be accessed and used by application server 255. If symmetric key 322 or 332 does not exist in in-memory cache 307, application server 255 may request that the security server derive symmetric key 322 or 332, receive the symmetric key, and use the regenerated symmetric key to decrypt the corresponding encrypted customer data.

[0057] FIG. 4 illustrates a specific embodiment of a flow diagram for method 400 for requesting a symmetric key generated using key agreement for encrypting and / or decrypting customer data. Process 600 may be performed by application server 255 (shown in FIG. 2) in communication with security server 260 and HSM 266. The key identifier may be received over a network connection from a security server, such as security server 260, during setup and stored by the application server (e.g., application server 255) in step 405. The key identifier may be one of many received from the security server, which may allocate multiple private keys for the application server to use against the security server. The key identifier may be associated with a private key that is accessible by the security server and inaccessible by the application server. In block 407, customer data may be received by the application server for storage, for example, in database 270. The customer data is encrypted before storage in database 270; therefore, receipt of the customer data by the application server triggers step 408. Alternatively, a request may be made by a customer for data that was previously encrypted by the application server and stored in database 270. The request may be made by a user using customer computing system 205 via an application program interface (API) or user interface (UI). Once the customer data is identified in the database, the symmetric key used to encrypt the customer data must be used to decrypt the customer data before sending the requested data to the customer.

[0058] In step 408, the application server 255 may determine whether the symmetric key 308 exists in the in-memory cache 307 of the application server 255. If the symmetric key 308 is found, the process proceeds to step 420, where the symmetric key 308 may be used to encrypt (or decrypt, if the customer is querying encrypted data stored in database 270) the customer data. The decrypted customer data may then be sent to the user, or, in the case of encryption, the encrypted customer data may be stored in the application server (e.g., database 270 or a similar data structure).

[0059] From block 408, if the application server 255 cannot find the symmetric key 322 in the in-memory cache 307, the symmetric key 322 needs to be derived. A request for the symmetric key may be sent from the application server to the security server in step 410. The request may be sent after the application server has stored the key identifier and may include the public key, salt value, and key identifier generated by the application server.

[0060] FIG. 5 shows a flowchart of an exemplary process for generating a request for a symmetric key generated using key agreement, according to some embodiments. In step 505, the application server may generate a public-private key pair, and the public key may be used to request the symmetric key. The public and private keys may be generated using any suitable method, including, but not limited to, elliptic curve cryptography (where both the public and private keys correspond to different points on an elliptic curve and are encrypted using elliptic curve cryptography). In step 510, a random salt value is generated and used to generate an unused key identifier from the security server pool. The random salt value may be randomly generated data used to generate each symmetric key, or a different salt number or string may be used for each symmetric key request. The salt value generally has enough bits to be unique among a potentially large number of clients; having more bits increases security but also increases the complexity (and potential time delay) of generating the symmetric key.

[0061] The key identifier may be selected from multiple key identifiers available to the application server 255 via the security server's key pool, a list of which has been previously sent to the application server as described above. Finally, a request including the generated public key, salt value, and key identifier may be sent by the application server to the security server in step 515. Furthermore, the combination of the public key, salt value, and key identifier may be stored in persistent storage (i.e., a data structure) of the application server so that the application server may easily regenerate the symmetric key at a later date.

[0062] 6 shows a simplified block diagram 600 including an example data structure 650 listing various symmetric keys assigned to different tenants in a multi-tenant environment, according to various embodiments. Diagram 600 includes a tenant-aware database 605 that may correspond to database 270 in communication with application server 255 of FIG. 2 , including data structure 650. Data structure 650 may be persistent storage that includes a combination of public keys, key identifiers (also referred to as key server IDs), and random salt values used to generate symmetric keys for multiple tenants (e.g., customers 315 and 325 of FIG. 3 ). Rows such as row 612 and row 618 of data structure 650 may correspond to individual symmetric keys used by the application server.

[0063] Symmetric keys for multiple tenants may be included in data structure 650, as exemplified by symmetric key entry 618, which has a different tenant ID 620 than symmetric key entry 612. As shown for symmetric key entry 612, each symmetric key entry may be associated with a tenant ID field value 615, a public key value 630 (associated with a public key generated by the application server when requesting the symmetric key corresponding to entry 612), a key identifier value 635 (associated with a private key accessible to the security server used to generate the symmetric key), and a salt value 640 (a randomly generated number or string, as shown). In situations where an application is decrypting customer data, metadata associated with the customer data may be used to identify which symmetric key in data structure 650 was used to encrypt the customer data. This metadata may include any identifying information that allows the application server to identify the symmetric key used for encryption, including, for example, public key value 630 for the symmetric key used to encrypt the customer data. Because the public key value for each symmetric key may be unique in various embodiments (i.e., public keys are not reused for different symmetric keys to provide greater security), the public key value 630 may be useful in identifying the symmetric key for purposes of decrypting encrypted customer data.

[0064] As noted in step 410 of FIG. 4 , the request for the symmetric key may be sent to a security server, which may generate the symmetric key using data specified by the request. FIG. 8 shows a flowchart of an exemplary process 800 performed in accordance with some embodiments for generating a symmetric key generated using key agreement. In some embodiments, the security server may be outside the control of the customer whose data is encrypted / decrypted by the symmetric key, although this is not necessarily the case. In some embodiments, the customer themselves may communicate with an HSM or other suitable key store to service using the customer-hosted key. In step 805, a request to derive a symmetric key is received from an application server at the security server, the request including the public key, salt value, and key identifier associated with the private key, as described above.

[0065] In response to receiving the request, the security server may derive a symmetric key using a key derivation function based on the received public key, salt value, and private key identified by the key identifier. The key derivation may begin in step 810 by retrieving the private key from a storage location inaccessible to the application server. Alternatively, the private key may be retrieved from a key management service in communication with the security server. The key management service may store multiple private keys (in an HSM or, for example, in storage under the control of the key management service) linked to multiple key identifiers provided to the security server. The key management service may take the form of an HSM that secures all private keys contained therein, which may be in communication with the security server via a network connection. Alternatively, the key management service may split the private key among multiple key servers, and private key sharing multi-party computing only allows a subset of the key servers (including the key management service server) to perform cryptographic computing that effectively enables access to the private key from the location where the key shares are stored, without actually assembling the private key on the key server. Such an embodiment may provide additional security by not storing private keys on the security server, but only providing them upon request. Alternatively, the storage location may be a data store within the security server. Figure 7 shows a simplified block diagram 700 illustrating an example data structure 730 that lists key identifiers (e.g., each row such as row 710) with their corresponding private keys, according to various embodiments.

[0066] A data structure 730 containing a list of asymmetric key pairs (public and private keys) may be stored within security server key bank 705, which may be an HSM, a key management service in communication with the security server, or, in various embodiments, a data store within the security server itself. Row 710 illustrates an asymmetric key pair record within private key data structure 730, listing the corresponding key identifier 715 for the asymmetric key pair and the private key 725 associated with the key identifier. Row 710 may also include a public key 720 associated with the private key 725, which, as shown in exemplary data structure 730, may be an elliptic curve public key generated by elliptic curve cryptography. Public key 720 may generally not be used to generate symmetric keys and, in some embodiments, may be discarded by the key service.

[0067] Returning to FIG. 8 , after obtaining the private key, a key agreement protocol may be applied to the public key and private key selected in the request by the key identifier in step 815 to obtain a key agreement key. Any suitable key agreement protocol may be used to generate the key agreement key from the public key and the private key associated with the key identifier, including Diffie-Hellman key exchange, anonymous key exchange, etc. In an exemplary embodiment, the key agreement protocol may be based on a common elliptic curve function for generating the public key and the private key associated with the key identifier. The public key and the private key associated with the key identifier may be derived from the same elliptic curve (albeit from separate elliptic curve key pairs corresponding to different points on the elliptic curve), and any suitable key agreement function may be applied to the private key associated with the public key and the key identifier. Such a function may be as simple as multiplying the public key and the private key associated with the key identifier to obtain a unique number. The use of key agreement may be advantageous over generating symmetric keys in other cryptographic methods, such as key wrapping, which are vulnerable to quantum computing attacks. In contrast, key agreement is generally more secure, even against quantum computing code-breaking techniques.

[0068] Finally, a symmetric key may be generated by the security server in step 820 by applying a key derivation function to the key-agreement key. The key derivation function may be a suitable cryptographic hash function that generates a symmetric key based on the key-agreement key and a salt value received in the request to derive the symmetric key. Exemplary key derivation functions that may be used include PBKDF2, bcrypt, scrypt, etc. After the symmetric key is generated, it may be sent to the requesting application server in step 825. As described below, the symmetric key may then be stored in an in-memory cache of the application server and used by the application server to encrypt customer data stored by the application server.

[0069] Returning to Figure 4, in step 420, the customer data may be encrypted by the application server using the received symmetric key. The encrypted customer data is protected from access by unauthorized users because possession of the symmetric key is required to decrypt the customer data. When the customer wishes to retrieve the customer data, the encrypted customer data may be decrypted using the symmetric key, which may be stored in the application server's cache memory or re-derived by the application server having access to the public key, salt value, and key identifier used to derive the symmetric key (e.g., via data structure 650). The decrypted customer data may then be transmitted to the customer.

[0070] The encrypted customer data may be stored in any persistent storage in communication with the application server and associated with the multi-tenant database environment. Examples of such persistent storage may be cloud-based storage areas, non-cloud-based storage areas, or other forms of storage implementation. Different tenants may utilize different persistent storage, which may be easily tracked by the application server using a unique tenant ID associated with one or more symmetric keys for each tenant in data structure 650.

[0071] Compared to conventional data protection schemes, method 400 advantageously does not require the persistence of private key data on either the application server or the security server (as in embodiments where the private key associated with the key identifier is stored in an HSM or other external storage), improving security by not including the symmetric key if either the application server or the security server is compromised. Because conventional systems require persisting the private key in cache memory, which can be resource-intensive in multi-tenant environments, method 400 not only improves security by not persisting the private key, but also reduces the amount of cache required. Only the public key used to generate the symmetric key is needed to regenerate the symmetric key after it has been removed from the cache. In some embodiments, the private key used by the application server to generate the public key may be discarded to conserve memory resources. Finally, method 400 represents a use of key agreement that differs from conventional usage. Conventionally, key agreement is typically used to secure communications between two devices; method 400 uses key agreement to securely generate a symmetric key to encrypt data from a third-party customer device not used to generate the symmetric key. As described above, symmetric keys generated using method 400 cannot be compromised by a single party, providing an inherent advantage to multi-tenant application servers for securing customer data.

[0072] Over time, it may be good practice for customers to rotate the symmetric key used to encrypt their data (i.e., use a different symmetric key to encrypt their data) to provide more security for encrypted data. To do so, the application server may simply send a new request to the security server for a different symmetric key. The request to rotate a symmetric key for a particular customer may be initiated by the customer, by an application server administrator, or automatically (e.g., after a predetermined period of time) by the application server, in various embodiments. FIG. 9 shows a flowchart of an example process 900 for performing key rotation on an application server, according to various embodiments. In step 905, the application server may send a request to rotate a symmetric key, where the rotation request includes a different public key generated by the application server, a different salt value, and a different key identifier associated with a different private key accessible to the private server. To improve security, requests for rotated symmetric keys use different elements because common elements may increase the likelihood that the rotated symmetric key will also be compromised if the current symmetric key is compromised.

[0073] After receiving the request to rotate the symmetric key, the security server may repeat the symmetric key generation process, for example, as illustrated by method 800 of Figure 8, using the different components received in the request to rotate the symmetric key. A different symmetric key may then be sent from the security server to the application server in response to the request to rotate the symmetric key at step 910. The different symmetric key may be derived based on a different public key and a different private key associated with a different key identifier using the key derivation function used to generate the symmetric key.

[0074] The different symmetric keys may be linked to the symmetric key, such as in a tenant key data structure, and may further be stored in an in-memory cache on the application server. Figure 10 shows an example data structure 1000 for storing entries 1010 of rotated symmetric keys for clients in a multi-tenant environment, according to various embodiments. Entry 1010 in the tenant key data structure is evidently the rotated symmetric key associated with entry 1005 because tenant ID 1009 matches tenant ID 1007. As explained above, the public key 1015, key identifier 1020, and salt value 1025 of the symmetric key associated with entry 1010 are unique to provide improved security over rotated keys.

[0075] Once a different symmetric key is cached, it may subsequently be used by the application server to encrypt data received from one of the multiple customer devices in step 915. In certain circumstances, it may be desirable to destroy a symmetric key previously used by a customer (e.g., if one of the components used to generate the symmetric key has been compromised). This may be accomplished by the application server removing the symmetric key from a list of symmetric keys associated with the application server (e.g., the tenant key data structure described above). The list of symmetric keys may be stored on the application server itself or in a database in communication with the application server, where the database also stores encrypted customer data. FIG. 11 shows an example data structure 1100 displaying the destruction of a symmetric key, according to various embodiments. Data structure 1100 is based on data structure 1000, where customer symmetric keys 1105 associated with tenant IDs 1007 and 1009 have been removed from the list of symmetric keys in data structure 1100. By deleting the public key 1120 and salt value 1125 for the symmetric key associated with entry 1105, there is no record of the recreation of the symmetric key associated with entry 1105. Without the symmetric key, any customer data encrypted with the symmetric key associated with entry 1105 cannot be decrypted. On-Demand Service Environment

[0076] FIG. 12A shows a system diagram 1200 illustrating architectural components of an on-demand service environment, according to some embodiments. Client machines located in cloud 1204 (or the Internet) may communicate with the on-demand service environment through one or more edge routers 1208 and 1212. The edge routers may communicate with one or more core switches 1220 and 1224 through a firewall 1216. The core switches may communicate with a load balancer 1228, which may distribute server loads to different pods, such as pods 1240 and 1244. Pods 1240 and 1244, each containing one or more servers and / or other computing resources, may perform data processing and other operations used to provide the on-demand service. Communication with the pods may occur through pod switches 1232 and 1236. Components of the on-demand service environment may communicate with a database storage system 1256 through a database firewall 1248 and a database switch 1252.

[0077] As shown in Figures 12A and 12B, accessing the on-demand service environment may involve communications transmitted between a variety of different hardware and / or software components. Furthermore, on-demand service environment 1200 is a simplified representation of an actual on-demand service environment. For example, while only one or two devices of each type are shown in Figures 12A and 12B, some embodiments of an on-demand service environment may include anywhere from one to many devices of each type. Also, an on-demand service environment need not include every device shown in Figures 12A and 12B, and may include additional devices not shown in Figures 12A and 12B.

[0078] Additionally, one or more of the devices in on-demand service environment 1200 may be implemented with the same physical device or different hardware. Some devices may be implemented using hardware or a combination of hardware and software. Thus, as used herein, terms such as "data processing device," "machine," "server," "device," etc. are not limited to a single hardware device, but rather include any hardware and software configured to provide the described functionality.

[0079] Cloud 1204 is intended to refer to a data network or multiple data networks, often including the Internet. Client machines located in cloud 1204 may communicate with the on-demand service environment to access services provided by the on-demand service environment. For example, client machines may access the on-demand service environment to retrieve, store, edit, and / or process information.

[0080] In some embodiments, edge routers 1208 and 1212 route packets between cloud 1204 and other components of on-demand service environment 1200. Edge routers 1208 and 1212 may use Border Gateway Protocol (BGP), which is a core routing protocol of the Internet. Edge routers 1208 and 1212 may maintain tables of IP networks or "prefixes" that specify network reachability between autonomous systems on the Internet.

[0081] In one or more embodiments, firewall 1216 may protect internal components of on-demand service environment 1200 from Internet traffic. Firewall 1216 may block, allow, or deny access to internal components of on-demand service environment 1200 based on a set of rules and other criteria. Firewall 1216 may function as one or more of a packet filter, an application gateway, a stateful filter, a proxy server, or any other type of firewall.

[0082] In some embodiments, core switches 1220 and 1224 are high-capacity switches that forward packets within on-demand service environment 1200. Core switches 1220 and 1224 may be configured as network bridges that quickly route data between different components within the on-demand service environment. In some embodiments, the use of two or more core switches 1220 and 1224 may provide redundancy and / or reduced latency.

[0083] In some embodiments, pods 1240 and 1244 may perform the core data processing and service functions provided by the on-demand service environment. Each pod may include various types of hardware and / or software computing resources. An example pod architecture is discussed in more detail with reference to FIG. 12B.

[0084] In some embodiments, communication between pods 1240 and 1244 may occur via pod switches 1232 and 1236. Pod switches 1232 and 1236 may facilitate communication between pods 1240, 1244 and client machines located in cloud 1204, for example, via core switches 1220, 1224. Pod switches 1232, 1236 may also facilitate communication between pods 1240, 1244 and database storage 1256.

[0085] In some embodiments, load balancer 1228 may distribute load among pods 1240 and 1244. Balancing on-demand service requests among pods may help improve resource usage, increase throughput, decrease response times, and / or reduce overhead. Load balancer 1228 may include multi-tier switches for analyzing and forwarding traffic.

[0086] In some embodiments, access to database storage 1256 may be guarded by database firewall 1248. Database firewall 1248 may function as a computer application firewall operating at the database application layer of the protocol stack. Database firewall 1248 may protect database storage 1256 from application attacks such as Structured Query Language (SQL) injection, database rootkits, and unauthorized information disclosure.

[0087] In some embodiments, database firewall 1248 may include hosts that use one or more forms of reverse proxy services to proxy traffic before passing it on to a gateway router. Database firewall 1248 may inspect the content of database traffic and block specific content or database requests. Database firewall 1248 operates at the SQL application level above the TCP / IP stack, managing application connections to the database or SQL administration interface, and intercepting and enforcing packets traveling to and from the database network or application interface.

[0088] In some embodiments, communication with database storage system 1256 may occur through database switch 1252. Multi-tenant database system 1256 may include multiple hardware and / or software components for processing database queries. Thus, database switch 1252 may direct database queries sent by other components of the on-demand service environment (e.g., pods 1240 and 1244) to the correct component within database storage system 1256. In some embodiments, database storage system 1256 is an on-demand database system shared by many different organizations. On-demand database systems may use a multi-tenant approach, a virtualization approach, or any other type of database approach. On-demand database systems are discussed in more detail with reference to FIGS. 13 and 14.

[0089] 13 shows a system diagram illustrating the architecture of a pod 1244, according to some embodiments. Pods 1244 may be used to provide services to users of on-demand service environment 1200. In some embodiments, each pod may include various services and / or other systems. Pod 1244 includes one or more content batch servers 1264, content search servers 1268, query servers 1272, file force servers 1276, access control system (ACS) servers 1280, batch servers 1284, and app servers 1288. Pod 1244 also includes database instance 1290, quick file system (QFS) 1292, and indexer 1294. In one or more embodiments, some or all of the communications between servers in pod 1244 may be transmitted through switch 1236.

[0090] In some embodiments, application server 1288 may include hardware and / or software frameworks dedicated to executing procedures (e.g., programs, routines, scripts) to support the construction of applications provided by on-demand service environment 1200 via pods 1244. Some such procedures may include operations to provide the services described herein. Content batch server 1264 may perform requests directed within a pod. These requests may be long-running and / or not tied to a particular customer. For example, content batch server 1264 may process requests related to log mining, cleanup work, and maintenance tasks.

[0091] The content retrieval server 1268 may provide query and indexer functionality. For example, the functionality provided by the content retrieval server 1268 may allow a user to search through content stored in the on-demand service environment. The file force server 1276 may manage requested information stored in the file force storage 1278. The file force storage 1278 may store documents, images, basic large objects (BLOBs), etc. By using the file force server 1276 to manage requests for information, the image footprint on the database may be reduced.

[0092] Query server 1272 may be used to retrieve information from one or more file systems. For example, query system 1272 may receive a request for information from app server 1288 and then send the information query to NFS 1296 located outside the pod. Pod 1244 may share database instance 1290 configured as a multi-tenant environment in which different organizations share access to the same database. Additionally, the services provided by pod 1244 may require various hardware and / or software resources. In some embodiments, ACS server 1280 may control access to data, hardware resources, or software resources.

[0093] In some embodiments, batch server 1284 may process batch jobs used to run tasks at specified times. Accordingly, batch server 1284 may send instructions to other servers, such as app server 1288, to trigger batch jobs. In some embodiments, QFS 1292 may be an open-source file system available from Sun Microsystems, Inc. of Santa Clara, California. QFS may serve as a fast-access file system for storing and accessing information available within pod 1244. QFS 1292 may support several volume management features, allowing many disks to be aggregated into a file system. File system metadata may be kept on a separate set of disks, which may be useful for streaming applications where long disk seeks cannot be tolerated. Accordingly, the QFS system may communicate with one or more content retrieval servers 1268 and / or indexers 1294 to identify, retrieve, move, and / or update data stored in network file system 1296 and / or other storage systems.

[0094] In some embodiments, one or more query servers 1272 may communicate with NFS 1296 to retrieve and / or update information stored outside of pod 1244. NFS 1296 may allow servers located in pod 1244 to access information for accessing files over a network in a manner similar to how local storage is accessed. In some embodiments, queries from query server 1222 may be sent to NFS 1296 via load balancer 1220, which may distribute resource requests over various resources available in an on-demand service environment. NFS 1296 may also communicate with QFS 1292 to update information stored therein and / or provide information to QFS 1292 for use by servers located within pod 1244.

[0095] In some embodiments, a pod may include one or more database instances 1290. Database instances 1290 may send information to QFS 1292. When information is sent to QFS, it may be available for use by servers in pod 1244 without requiring additional database calls. In some embodiments, the database information may be sent to indexer 1294. Indexer 1294 may provide an index of the information available in database 1290 and / or QFS 1292. The index information may be provided to file force server 1276 and / or QFS 1292.

[0096] 13 shows a block diagram of an environment 1310 in which an on-demand database service may be used, according to some embodiments. The environment 1310 includes an on-demand database service 1316. A user system 1312 may be any machine or system used by a user to access a database user system. For example, any of the user systems 1312 may be a handheld computing system, a mobile phone, a laptop computer, a workstation, and / or a network of computing systems. As illustrated in FIGS. 13 and 14 , the user system 1312 may interact with the on-demand database service 1316 via a network 1314.

[0097] An on-demand database service, such as system 1316, does not necessarily involve building and / or maintaining a database system, but instead is a database system made available to external users that may be available for their use when a user needs the database system (e.g., upon user request). Some on-demand database services may store information from one or more tenants stored in tables of a common database image, forming a multi-tenant database system (MTS). Thus, “on-demand database service 1316” and “system 1316” are used interchangeably herein. A database image may include one or more database objects. A relational database management system (RDBMS) or its equivalent may perform the storage and retrieval of information for the database objects. An application platform 1318 may be a framework, such as an operating system, that enables applications of system 1316 to operate hardware, software, etc. In one implementation, on-demand database service 1316 may include an application platform 1318 that enables the creation, management, and execution of one or more applications developed by the on-demand database service provider, a user accessing the on-demand database service via user system 1312, or a third-party application developer accessing the on-demand database service via user system 1312.

[0098] 13, which includes a network interface 1320, an application platform 1318, tenant data storage 1322 for tenant data 1323, system data storage 1324 for system data 1325 accessible to the system 1316 and possibly multiple tenants, program code 1326 for implementing various functions of the system 1316, and a process space 1328 for running MTS system processes and tenant-specific processes, such as those that run applications as part of an application hosting service. Additional processes that may run on the system 1316 include a database index process.

[0099] Users of user system 1312 may have different capacities, and the capacity of a particular user system 1312 may be determined entirely by the permissions (permission level) for the current user. For example, if a call center agent is using a particular user system 1312 to interact with system 1316, then user system 1312 has a capacity assigned to that call center agent. However, if an administrator is using that user system to interact with system 1316, then that user system has a capacity assigned to that administrator. In a system with a hierarchical role model, a user at one permission level may have access to applications, data, and database information accessible to users at a lower permission level, but may not have access to certain applications, database information, and data accessible to users at a higher permission level. Thus, different users may have different capabilities with respect to accessing and modifying application and database information, depending on the user's security or permission level.

[0100] Network 1314 is a network or combination of devices that communicate with each other. For example, network 1314 can be any one or combination of a local area network (LAN), a wide area network (WAN), a telephone network, a wireless network, a point-to-point network, a star network, a token ring network, a hub network, or any other suitable configuration. Because the most common type of computer network in use today is a Transfer Control Protocol and Internet Protocol (TCP / IP) network (e.g., the Internet), that network will be used throughout much of this specification. However, it should be understood that while TCP / IP is a frequently implemented protocol, the network used in some embodiments is not so limited.

[0101] User system 1312 communicates with system 1316 using TCP / IP and, at higher network levels, may communicate using other common Internet protocols such as HTTP, FTP, AFS, WAP, etc. In examples where HTTP is used, user system 1312 may include an HTTP client, commonly referred to as a "browser," to send and receive HTTP messages to and from an HTTP server in system 1316. Such an HTTP server may be implemented as the only network interface between system 1316 and network 1314, although other technologies may also or alternatively be used. In some embodiments, the interface between system 1316 and network 1314 includes a load-sharing function, such as a round-robin HTTP request distributor, to balance the load and distribute incoming HTTP requests evenly across multiple servers. Each of the multiple servers, as well as at least the users accessing that server, may have access to the MTS data, although other alternative configurations may alternatively be used.

[0102] In some embodiments, system 1316 shown in FIG. 13 implements a web-based customer relationship management (CRM) system. For example, in some embodiments, system 1316 includes an application server configured to implement and run a CRM software application, provide associated data, code, forms, web pages, and other information to and from user system 1312, and store and retrieve associated data, objects, and web page content to and from a database system. In a multi-tenant system, data for multiple tenants may be stored in the same physical database object, but tenant data is typically arranged so that one tenant's data is logically separated from other tenants' data and one tenant does not have access to other tenants' data unless such data is explicitly shared. In particular embodiments, system 1316 implements applications other than or in addition to a CRM application. For example, system 1316 may provide tenant access to multiple hosted applications (standard and custom). User (or third-party developer) applications, which may or may not include a CRM, may be supported by an application platform 1318, which manages the creation of the applications, their storage in one or more database objects, and their execution in virtual machines in the process space of the system 1316.

[0103] Each user system 1312 may include a desktop personal computer, a workstation, a laptop, a PDA, a mobile phone, or any Wireless Access Protocol (WAP)-enabled device, or any other computing system capable of interfacing directly or indirectly with the Internet or other network connection. User system 1312 typically operates an HTTP client, e.g., a browser program such as Microsoft's Internet Explorer® browser, Mozilla's Firefox® browser, Opera's browser, or a WAP-enabled browser for a mobile phone, PDA, or other wireless device, to enable a user of user system 1312 (e.g., a subscriber to the multi-tenant database system) to access, process, and view information, pages, and applications available to it from system 1316 via network 1314.

[0104] Each user system 1312 also typically includes one or more user interface devices, such as a keyboard, mouse, trackball, touchpad, touchscreen, pen, etc., for interacting with a graphical user interface (GUI) provided by a browser on a display (e.g., a monitor screen, LCD display, etc.) in conjunction with pages, forms, applications, and other information provided by system 1316 or other systems or servers. For example, the user interface devices may be used to access data and applications hosted by system 1316, perform searches on stored data, and otherwise enable a user to interact with various GUI pages that may be presented to the one or more users. As discussed above, embodiments are suitable for use with the Internet, which refers to a specific global internetwork of networks. However, it should be understood that other networks, such as an intranet, an extranet, a virtual private network (VPN), a non-TCP / IP-based network, any LAN or WAN, etc., may be used in place of the Internet.

[0105] According to some embodiments, each user system 1312 and all of its components are operator-configurable using an application, such as a browser, that includes computer code operating using a central processing unit, such as an Intel Pentium processor. Similarly, system 1316 (and additional instances of MTS, of which there may be multiple) and all of their components may be operator-configurable using an application, such as a browser, that includes computer code operating using a central processing unit, such as processor system 1317, which may include an Intel Pentium processor, and / or multiple processor units.

[0106] A computer program product implementation includes machine-readable storage medium(s) having instructions stored thereon, which can be used to program a computer to perform any of the processes of the embodiments described herein. The computer code for operating and configuring system 1316 to interact with and process web pages, applications, and other data and media content described herein is preferably downloaded and stored on a hard disk, although the entire program code, or portions thereof, may also be stored in any other volatile or non-volatile memory medium or device, such as ROM, RAM, or provided on any medium capable of storing program code, such as any type of rotating medium, including floppy disks, optical disks, digital versatile disks (DVDs), compact disks (CDs), microdrives, and magneto-optical disks, magnetic or optical cards, nanosystems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data. Additionally, the entire program code, or portions thereof, may be transmitted and downloaded from a software source or from another server via a transmission medium, for example, via the Internet, or may be transmitted via any other conventional network connection (e.g., extranet, VPN, LAN, etc.) using a communication medium and protocol (e.g., TCP / IP, HTTP, HTTPS, Ethernet, etc.). It will also be understood that computer code for implementing embodiments may be written in any programming language executable on the client system(s) and / or server or server systems, such as C, C++, HTML, any other markup language, Java™, JavaScript™, ActiveX™, any other scripting language such as VBScript, or many other well-known programming languages. (Java™ is a trademark of Sun Microsystems™, Inc.)

[0107] According to some embodiments, each system 1316 is configured to provide web pages, forms, applications, data, and media content to user (client) systems 1312 to support access by user systems 1312 as tenants of the system 1316. Thus, the system 1316 provides security mechanisms to keep each tenant's data separate unless the data is shared. When multiple MTSs are used, they may be located in close proximity to one another (e.g., a server farm located in a single building or campus) or in locations remote from one another (e.g., one or more servers located in City A and one or more servers located in City B). As used herein, each MTS may include logically and / or physically connected servers that are local or distributed across one or more geographic locations. Additionally, the term "server" is meant to include computing systems known in the art, including processing hardware and processing space, as well as associated storage systems and database applications (e.g., OODBMS or RDBMS).

[0108] It should also be understood that "server system" and "server" are often used interchangeably herein. Similarly, the database objects described herein may be implemented as a single database, a distributed database, a collection of distributed databases, a database with online or offline redundant backups or other redundancies, etc., and may include a distributed database or storage network and associated processing intelligence.

[0109] FIG. 14 also shows a block diagram of environment 1310 further illustrating system 1316 and various interconnections, according to some embodiments. Figure 14 illustrates that user system 1312 may include processor system 1312A, memory system 1312B, input system 1312C, and output system 1312D. Figure 14 illustrates network 1314 and system 1316. Figure 14 also illustrates that system 1316 may include tenant data storage 1322, tenant data 1323, system data storage 1324, system data 1325, user interface (UI) 1430, application program interface (API) 1432, PL / SOQL 1434, save routines 1436, application setup mechanism 1438, application servers 14001-1400N, system process space 1402, tenant process space 1404, tenant management process space 1410, tenant storage area 1412, user storage 1414, and application metadata 1416. In other embodiments, environment 1310 may not have the same elements as those listed above and / or may have other elements instead of or in addition to those listed above.

[0110] The user system 1312, network 1314, system 1316, tenant data storage 1322, and system data storage 1324 were discussed above in FIG. 13 . With respect to the user system 1312, the processor system 1312A may be any combination of processors. The memory system 1312B may be any combination of one or more memory devices, short-term memory, and / or long-term memory. The input system 1312C may be any combination of input devices such as a keyboard, mouse, trackball, scanner, camera, and / or interface to a network. The output system 1312D may be any combination of output devices such as a monitor, printer, interface to a network, etc. As shown in FIG. 14 , the system 1316 may include a network interface 1320 (of FIG. 13 ), an application platform 1318, tenant data storage 1322, and system data storage 1324, implemented as a set of HTTP application servers 1400. Also shown is a system process space 1402, including individual tenant process spaces 1404 and a tenant management process space 1410. Each application server 1400 may be configured to service the requests of user systems 1312 with data storage 1322 and tenant data 1323 therein, and system data storage 1324 and system data 1325 therein. Tenant data 1323 may be divided into individual tenant storage areas 1412, which may be either a physical and / or logical arrangement of data. Within each tenant storage area 1412, user storage 1414 and application metadata 1416 may be similarly allocated for each user. For example, a copy of a user's most recently used (MRU) items may be stored in user storage 1414. Similarly, a copy of the MRU items for the entire tenant organization may be stored in tenant storage area 1412.UI 1430 provides a user interface and API 1432 provides an application programmer interface to the system 1316 resident processes for users and / or developers of user system 1312. Tenant data and system data may be stored in various databases, such as an Oracle™ database.

[0111] The application platform 1318 includes an application setup mechanism 1438 that supports the creation and management of applications by application developers, which may be saved as metadata in tenant data storage 1322, for example, by a save routine 1436 for subscriber execution as tenant process space 1404 managed by tenant management process 1410. Invocation of such applications may be coded using PL / SOQL 34, which provides a programming language-style interface extension to API 1432. A detailed description of several PL / SOQL language embodiments is discussed in commonly assigned U.S. Patent No. 7,730,478, by Craig Weissman, entitled "METHOD AND SYSTEM FOR ALLOWING ACCESS TO DEVELOPED APPLICATIONS VIA A MULTI-TENANT ON-DEMAND DATABASE SERVICE," filed September 21, 2007, which is incorporated herein by reference in its entirety for all purposes. The application invocation may be detected by a system process that manages obtaining the application metadata 1416 for the subscriber to make the invocation and running the metadata as an application within a virtual machine.

[0112] Each application server 1400 may be communicatively coupled to the database system via a different network connection, e.g., having access to system data 1325 and tenant data 1323. For example, one application server 14001 may be coupled via a network 1314 (e.g., the Internet), another application server 1400N-1 may be coupled via a direct network link, and another application server 1400N may be coupled by yet another network connection. TCP / IP (Transfer Control Protocol and Internet Protocol) is a typical protocol for communicating between the application servers 1400 and the database system. However, other transport protocols may be used to optimize the system depending on the network interconnect used.

[0113] In particular embodiments, each application server 1400 is configured to process requests for any user associated with any tenant organization. Because it may be desirable to add and remove application servers from the server pool at any time for any reason, there is preferably no server affinity for users and / or organizations to a particular application server 1400. Accordingly, in some embodiments, an interface system implementing load balancing functionality (e.g., an F5 Big IP Load Balancer) is communicatively coupled between the application servers 1400 and the user systems 1312 to distribute requests to the application servers 1400. In some embodiments, the load balancer uses a least-connections algorithm to route user requests to the application servers 1400. Other examples of load balancing algorithms, such as round robin and observed response time, may also be used. For example, in particular embodiments, three consecutive requests from the same user may hit three different application servers 1400, and three requests from different users may hit the same application server 1400. In this manner, the system 1316 is multi-tenant; the system 1316 handles the storage of and access to different objects, data, and applications across disparate users and organizations.

[0114] As an example of storage, one tenant might be a company that hires sales personnel, with each call center agent using system 1316 to manage their sales process. Thus, a user might maintain (e.g., in tenant data storage 1322) contact data, lead data, customer follow-up data, performance data, goals, progress data, etc., all applicable to that user's personal sales process. In one example of an MTS deployment, all of the data and applications for accessing, viewing, modifying, reporting, transmitting, calculating, etc., are maintained and accessible by user systems with nothing more than network access, allowing users to manage their sales efforts and cycles from any of many different user systems. For example, if a call center agent is visiting a customer and the customer has Internet access in the lobby, the call center agent can retrieve important updates about the customer while waiting for the customer to arrive in the lobby.

[0115] While each user's data may be isolated from other users' data, regardless of their employer, some data may be organization-wide data that can be shared or accessed by multiple users or all users for a given organization that is a tenant. Thus, some data structures managed by system 1316 may be allocated at the tenant level, while other data structures may be managed at the user level. Because an MTS may support multiple tenants, including potentially competitors, the MTS should have security protocols that keep data, applications, and application usage separate. Additionally, because many tenants may choose to access the MTS rather than maintain their own systems, redundancy, uptime, and backups are additional features that may be implemented in the MTS. In addition to user-specific and tenant-specific data, system 1316 may also maintain system-level data that can be used by multiple tenants or other data. Such system-level data may include industry reports, news, posts, and the like that can be shared among tenants.

[0116] In particular embodiments, user system 1312 (which may be a client machine / system) communicates with application server 1400 to request and update system-level and tenant-level data from system 1316, which requires sending one or more queries to tenant data storage 1322 and / or system data storage 1324. System 1316 (e.g., application server 1400 of system 1316) automatically generates one or more SQL statements (e.g., SQL queries) designed to access the desired information. System data storage 1324 may generate a query plan to access the requested data from the database.

[0117] Each database can generally be thought of as a collection of objects, such as a set of logical tables, containing data that fits into predefined categories. A "table" is one representation of a data object and may be used herein to simplify the conceptual description of objects and custom objects according to some embodiments. It should be understood that the terms "table" and "object" may be used interchangeably herein. Each table contains one or more data categories logically arranged as columns or fields within a viewable schema. Each row or record in a table contains an instance of data in each category defined by the fields. For example, a CRM database may include a table that lists customers, with fields for basic contact information such as name, address, phone number, and fax number. Another table might list orders, with fields for information such as customer, product, sales price, and date. In some multi-tenant database systems, standard entity tables may be provided for use by all tenants. In a CRM database application, such standard entities include tables for account, contact, lead, and opportunity data, each containing predefined fields. It should be understood that the word "entity" may also be used interchangeably with "object" and "table" herein.

[0118] In some multi-tenant database systems, tenants may be able to create and store custom objects or customize standard entities or objects by, for example, creating custom fields for standard objects, including custom index fields. U.S. Patent No. 7,779,039, entitled "CUSTOM ENTITIES AND FIELDS IN A MULTI-TENANT DATABASE SYSTEM," by Weissman et al., is incorporated herein by reference in its entirety, and teaches a system and method for creating custom objects and customizing standard objects in a multi-tenant database system for all purposes. In some embodiments, for example, all custom entity data rows are stored in a single multi-tenant physical table, which may include multiple logical tables for each organization. In some embodiments, multiple "tables" for a single customer may actually be stored in one large table and / or the same table as other customers' data.

[0119] These and other aspects of the present disclosure may be implemented by various types of hardware, software, firmware, etc. For example, some features of the present disclosure may be implemented, at least in part, by a machine-readable medium containing program instructions, state information, etc. for performing various operations described herein. Examples of program instructions include both machine code, such as produced by a compiler, and files containing high-level code that may be executed by a computer using an interpreter. Examples of machine-readable media include, but are not limited to, magnetic media, such as hard disks, floppy disks, and magnetic tape; optical media, such as CD-ROM disks; magneto-optical media; and hardware devices specifically configured to store and execute program instructions, such as read-only memory devices (“ROM”), random access memory (“RAM”), etc.

[0120] Although one or more embodiments and techniques are described with reference to an implementation in which a service cloud console is implemented in a system having an application server that provides a front end for an on-demand database service capable of supporting multiple tenants, the one or more embodiments and techniques are not limited to multi-tenant databases or deployment on application servers. Embodiments may be implemented using other database architectures, i.e., ORACLE®, DB2® by IBM, etc., without departing from the scope of the claimed embodiments.

[0121] Any of the above embodiments may be used alone or in conjunction with each other in any combination. Various embodiments may be motivated by various deficiencies in the prior art, which may be discussed or alluded to in one or more places in the specification, but an embodiment does not necessarily address all of these deficiencies. In other words, different embodiments may address different deficiencies that may be discussed herein. Some embodiments may only partially address several deficiencies, or even just one deficiency, that may be discussed herein, and some embodiments may not address any of these deficiencies.

[0122] While various embodiments have been described herein, it should be understood that these are presented by way of example, and not limitation. Thus, the breadth and scope of the present disclosure should not be limited by any of the embodiments described herein, but should be defined only in accordance with the following claims and their equivalents. This specification also discloses the following: (Appendix 1) 1. A computer-implemented method for securing client data using a security server, comprising: receiving, by a security server, a request to derive a symmetric key from an application server, the request including a public key, a salt value, and a key identifier associated with a private key; deriving, by the security server, the symmetric key using a key derivation function based on the received public key and the private key associated with the key identifier; retrieving the private key associated with the key identifier from a storage location that is inaccessible to the application server; applying a key agreement protocol to the received public key and the obtained private key associated with the key identifier, the key agreement protocol outputting a key agreement key; applying a key derivation function to the key-agreement key to generate the symmetric key; and transmitting, by the security server, the derived symmetric key to the requesting application server, where the symmetric key is then stored in an in-memory cache of the application server and used by the application server to encrypt customer data. (Appendix 2) 2. The method of claim 1, wherein the security server stores a list of asymmetric key pairs for multiple tenants, each asymmetric key pair including a public key and a private key, and each private key is associated with a corresponding key identifier. (Appendix 3) 2. The method of claim 1, further comprising deleting, by the security server, the derived symmetric key after sending the derived symmetric key to the requesting application server. (Appendix 4) 2. The method of claim 1, wherein both the public key and the private key associated with the key identifier correspond to different points on an elliptic curve. (Appendix 5) 2. The method of claim 1, wherein the key agreement protocol for generating the key agreement key is based on an elliptic curve common to both the received public key and the obtained private key associated with the key identifier. (Appendix 6) 2. The method of claim 1, wherein the key agreement protocol is a Diffie-Hellman key exchange. (Appendix 7) 2. The method of claim 1, wherein the private key is obtained from a key management service in communication with the security server, the key management service storing multiple private keys accessible to the security server. (Appendix 8) 1. An apparatus for securing customer data, comprising: one or more processors of a security server; A non-transitory computer-readable medium storing a plurality of instructions that, when executed, cause the one or more processors to: receiving a request to derive a symmetric key from an application server, the request including a public key, a salt value, and a key identifier associated with a private key; deriving the symmetric key using a key derivation function based on the received public key and the private key associated with the key identifier; retrieving the private key associated with the key identifier from a storage location that is inaccessible to the application server; applying a key agreement protocol to the received public key and the obtained private key associated with the key identifier, the key agreement protocol outputting a key agreement key; applying a key derivation function to the key-agreement key to generate the symmetric key; and sending the derived symmetric key to the requesting application server, where the symmetric key is stored in an in-memory cache of the application server and used by the application server to encrypt customer data. (Appendix 9) 9. The apparatus of Claim 8, wherein the instructions further include instructions for causing the one or more processors to store a list of asymmetric keys for a plurality of tenants, each asymmetric key pair including a public key and a private key, and each private key associated with a corresponding key identifier. (Appendix 10) 9. The apparatus of claim 8, wherein the instructions further include instructions to cause the one or more processors to delete the derived symmetric key by the security server after sending the derived symmetric key to the requesting application server. (Appendix 11) 9. The apparatus of claim 8, wherein both the public key and the private key associated with the key identifier correspond to different points on an elliptic curve. (Appendix 12) 9. The apparatus of claim 8, wherein the key agreement protocol for generating the key agreement key is based on an elliptic curve common to both the received public key and the obtained private key associated with the key identifier. (Appendix 13) 9. The apparatus of claim 8, wherein the key agreement protocol is a Diffie-Hellman key exchange. (Appendix 14) 9. The apparatus of claim 8, wherein the private key is obtained from a key management service that stores multiple private keys accessible to the security server. (Appendix 15) 1. A computer program product comprising computer-readable program code that is executed by one or more processors when obtained from a non-transitory computer-readable medium, the program code comprising: receiving a request to derive a symmetric key from an application server, the request including a public key, a salt value, and a key identifier associated with a private key; deriving the symmetric key using a key derivation function based on the received public key and the private key; retrieving the private key from a storage location that is inaccessible to the application server; applying a key agreement protocol to the received public key and the obtained private key using an elliptic curve common to both the received public key and the obtained private key, the key agreement protocol outputting a key agreement key; applying a key derivation function to the key-agreement key to generate the symmetric key; and sending the derived symmetric key to the requesting application server, wherein the symmetric key is stored in an in-memory cache of the application server and used by the application server to encrypt customer data. (Appendix 16) 16. The computer program product of Claim 15, further comprising instructions for storing a list of asymmetric keys for a plurality of tenants, the application server being associated with one of the plurality of tenants, each symmetric key in the list being associated with a public key accessible to the tenant and a private key accessible to the security server and inaccessible to the plurality of tenants. (Appendix 17) 16. The computer program product of Claim 15, further comprising instructions for deleting the derived symmetric key after sending the derived symmetric key to the requesting application server. (Appendix 18) 16. The computer program product of Claim 15, wherein the key agreement protocol for generating the key agreement key is based on an elliptic curve common to both the received public key and the obtained private key associated with the key identifier. (Appendix 19) 16. The computer program product of claim 15, wherein the key agreement protocol is a Diffie-Hellman key exchange. (Appendix 20) 16. The computer program product of claim 15, wherein the private key is obtained from a key management service in communication with the security server, the key server including a hardware security module (HSM) that stores multiple private keys linked to multiple public keys provided to the security server.

Claims

1. 1. A computer-implemented method for securing client data using a security server, comprising: receiving, by a security server, a request to derive a symmetric key from an application server, the request including a public key, a salt value, and a key identifier associated with a private key; deriving, by the security server, the symmetric key using a key derivation function based on the received public key and the private key associated with the key identifier; retrieving the private key associated with the key identifier from a storage location that is inaccessible to the application server; applying a key agreement protocol to the received public key and the obtained private key associated with the key identifier, the key agreement protocol outputting a key agreement key; applying a key derivation function to the key-agreement key to generate the symmetric key; and transmitting, by the security server, the derived symmetric key to the requesting application server, where the symmetric key is then stored in an in-memory cache of the application server and used by the application server to encrypt customer data.

2. 2. The method of claim 1, wherein the security server stores a list of asymmetric key pairs for multiple tenants, each asymmetric key pair including a public key and a private key, and each private key is associated with a corresponding key identifier.

3. The method of claim 1 , further comprising deleting, by the security server, the derived symmetric key after sending the derived symmetric key to the requesting application server.

4. The method of claim 1 , wherein both the public key and the private key associated with the key identifier correspond to different points on an elliptic curve.

5. The method of claim 1 , wherein the key agreement protocol for generating the key agreement key is based on an elliptic curve common to both the received public key and the obtained private key associated with the key identifier.

6. The method of claim 1 , wherein the key agreement protocol is a Diffie-Hellman key exchange.

7. The method of claim 1 , wherein the private key is obtained from a key management service in communication with the security server, the key management service storing a plurality of private keys accessible to the security server.

8. 1. An apparatus for securing customer data, comprising: one or more processors of a security server; 8. A non-transitory computer-readable medium storing a plurality of instructions that, when executed, cause the one or more processors to perform the method of any one of claims 1 to 7.

9. 8. A computer program comprising computer readable program code that, when obtained from a non-transitory computer readable medium, is executed by one or more processors, the program code causing the one or more processors to perform a method according to any one of claims 1 to 7.

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