Identity-based digital signature encryption method and system in Internet of Things environment

Abstract

The invention discloses an identity-based digital signature encryption method and system in an Internet of Things environment, and belongs to the technical field of Internet of Things security. The method comprises the following steps that: a key generation center KGC generates system parameters which comprise a bilinear mapping parameter, a hash function and a master key, and publishes a public parameter; receiving registration information submitted by a user or equipment to the KGC by using own identity information, and calculating and distributing a corresponding private key by the KGC according to the identity information; the sender encrypts the message by using the identity information of the receiver and signs the message by using a private key of the sender; and the receiver verifies the validity of the signature by using the identity information of the sender, and decrypts the message by using a private key of the receiver. According to the invention, the identity-based digital signature encryption is introduced into the communication of the Internet of Things, and through the design of the identity, namely the public key, the lightweight, efficient and flexible communication security guarantee of the Internet of Things is realized, the key and identity management is simplified, the efficient equipment authentication and dynamic access are realized, and the security and mutual trust of cross-scene communication are ensured.

Description

Technical Field

[0001] This invention relates to the field of Internet of Things (IoT) security technology, specifically an identity-based digital signature encryption method and system for IoT environments, which can be widely applied to scenarios such as smart terminals, smart homes, smart industrial control, vehicle networking, smart transportation, smart logistics, and smart agriculture in the IoT field. Background Technology

[0002] With the emergence and development of the Internet of Things (IoT), the underlying IoT technologies, network communication technologies, cloud computing technologies, human-computer interaction technologies, and so on are becoming increasingly powerful. IoT technology is deeply penetrating into fields such as smart homes, industrial control, smart cities, and telemedicine. The number of IoT devices worldwide has exceeded 10 billion, and it exhibits typical characteristics of "wide distribution of nodes, large differences in resources, and fragmented scenarios".

[0003] The rapid development of IoT applications has made communication authentication for various IoT terminals and thin servers particularly important. IoT devices and applications are now widely used in people's work and lives. However, this is accompanied by numerous security issues, such as the rampant spread of personal and private data, the leakage of transmitted information, the tampering of operation instructions during issuance, the monitoring and manipulation of IoT devices, and denial-of-service attacks that render devices unusable. These security issues affect all aspects of life, and can lead not only to information leaks and damage to property, but also, in severe cases, to personal safety. When the scale and scope of the impact are large enough, they can even affect social and national stability, thus rising to the level of national strategic security.

[0004] Therefore, the communication security needs (device authentication, data encryption, anti-tampering, and privacy protection) in the above-mentioned IoT scenarios are becoming increasingly urgent, but traditional cryptographic solutions (such as those based on public key infrastructure (PKI)) face significant adaptation bottlenecks: including the limited computing power of low-power IoT devices, which cannot support the certificate verification process; the contradiction between the dynamism of IoT nodes and the complexity of certificate management; and the contradiction between end-to-end computing and "lightweight" and "high security" in the IoT environment.

[0005] The aforementioned bottlenecks make it difficult for traditional cryptographic schemes to meet the communication security requirements of the Internet of Things (IoT) in terms of large scale, lightweight design, and dynamic operation, which has become a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of the above problems, the present invention provides an identity-based digital signature encryption method and system for IoT environments. By introducing identity-based digital signature (IBS) and identity-based encryption (IBE) from identity-based cryptography (IBC), an identity-based digital signature encryption IBS-IBE scheme for IoT environments is proposed. This avoids the problems of complex certificate management and weak computing power of IoT devices under traditional PKI systems. By using identity-based digital signature encryption, high communication security and low communication computing cost are achieved in IoT systems.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, embodiments of the present invention provide an identity-based digital signature encryption method in an Internet of Things (IoT) environment, comprising the following steps: System setup steps: The Key Generation Center (KGC) generates system parameters, including bilinear mapping parameters, hash functions, and master keys, and publishes the public parameters; Key extraction steps: Receive registration information submitted by the user or device using their own identity information to KGC; KGC calculates and distributes the corresponding private key based on the identity information. Signature encryption steps: The sender encrypts the message using the recipient's identity information and signs the message with its own private key; Signature verification and decryption steps: The recipient uses the sender's identity information to verify the signature's legitimacy and then uses their own private key to decrypt the message.

[0008] In one embodiment, the system setup steps include: (1) Key generation center KGC generates bilinear parameters ,in yes Additive cyclic group of order, yes Multiplicative cyclic group of order, It is a group The two generators, It is a bilinear mapping, representing ; (2) KGC selects two hash functions ; , , The length of the message; (3) KGC selects a random number As the master key And calculate the public key. ; (4) Common parameters of KGC publishing system .

[0009] In one embodiment, the key extraction step includes: (1) KGC receives registration requests submitted by users or devices using their own identity information ID; (2) KGC calculates R based on the identity information ID. (ID), and use the master key s to generate the private key S=s·R·Q; send {R,S} and system parameters to the corresponding user or device through a secure channel.

[0010] In one embodiment, the signature encryption step includes: (1) The sender selects a random number r; (2) The sender calculates the ciphertext C=r·P and the encryption key. encrypt message M to obtain and generate a signature. ,in ; (3) The sender obtains the current timestamp The calculated ciphertext, the encrypted ciphertext of the message, the ciphertext signature, and the timestamp are sent to the corresponding recipient.

[0011] In one embodiment, the signature verification and decryption step includes: (1) Calculation by the recipient , Check at the current time. Whether it is valid, Let be any small positive number; if true, verify the equation. Are they equal? (2) If they are equal, then decrypt the message. ,in .

[0012] In a second aspect, embodiments of the present invention provide an Internet of Things security system for implementing the method described in any of the first aspects, including: a smart terminal device, a user, and a key generation center (KGC); The key generation center (KGC) is used to perform the system establishment steps and key extraction steps. The smart terminal device and the user are used to perform the signature encryption step and the signature verification and decryption step.

[0013] As can be seen from the above technical solution, compared with the prior art, the present invention has the following technical effects: This invention can be used to ensure user privacy, user access security, and normal device operation, thereby improving IoT security, reducing IoT communication and computing costs, and facilitating the large-scale deployment and scenario-based penetration of IoT security. This invention addresses the mismatch between the weak computing and storage capabilities of IoT devices and their high security requirements, ensuring identity authentication of smart devices in the IoT environment, and guaranteeing the authenticity and integrity of data transmission; it also reduces the costs of certificate usage and management. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0015] Figure 1 This is a flowchart of an identity-based digital signature encryption method in an IoT environment provided in this embodiment of the invention; Figure 2 This is a schematic diagram of an identity-based digital signature encryption scenario in an IoT environment provided in this embodiment of the invention. Figure 3 This is a schematic diagram illustrating the user and device registration scenario provided in this embodiment of the invention. Figure 4 This is a schematic diagram of the authentication and key negotiation scenario provided in the embodiments of the present invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] While IoT technology brings convenience to people, ensuring end-to-end security within IoT systems is of paramount importance. This invention introduces identity-based digital signature encryption into IoT communication, employing a "identity as public key" design to achieve lightweight, efficient, and flexible IoT communication security. It simplifies key and identity management, enables efficient device authentication and dynamic access, and ensures secure and trustworthy cross-scenario communication.

[0018] Reference Figure 1 As shown in the figure, this invention discloses an identity-based digital signature encryption method in an Internet of Things (IoT) environment, comprising the following steps: System setup steps: The Key Generation Center (KGC) generates system parameters, including bilinear mapping parameters, hash functions, and master keys, and publishes the public parameters; Key extraction steps: Receive registration information submitted by the user or device using their own identity information to KGC; KGC calculates and distributes the corresponding private key based on the identity information. Signature encryption steps: The sender encrypts the message using the recipient's identity information and signs the message with its own private key; Signature verification and decryption steps: The recipient uses the sender's identity information to verify the signature's legitimacy and then uses their own private key to decrypt the message.

[0019] This invention designs an identity-based digital signature encryption (IBS-IBE) scheme for IoT environments to facilitate communication between devices or between users and devices. IBS-IBE enables rapid identity authentication, ensuring the authenticity and integrity of data transmission. The scheme involves three parties: smart terminal devices, users, and a key management center. After registering with the key management center, users and smart devices extract their personal key information. Then, both parties perform identity-based digital signatures, ultimately enabling information transmission and various command operations between devices and between users and devices. The principle is as follows: Figure 2 As shown.

[0020] This invention designs a lightweight identity authentication scheme for device-to-device or user-to-device interactions in IoT scenarios. The scheme solves the overhead and management problems associated with a large number of smart device certificates in IoT environments, and simultaneously implements a lightweight digital signature encryption scheme adapted to the low computing power and low storage requirements of IoT thin clients to complete identity authentication. The identity-based digital signature encryption IBS-IBE scheme mainly includes four stages: system setup, key extraction, signature encryption, and signature verification / decryption.

[0021] The system setup phase involves the key generation center generating system parameters; the key extraction phase involves the key generation center calculating the private key corresponding to each user and device's identity; the signature encryption phase involves the sender encrypting the message using the receiver's identity information and signing the message using their own private key; and the signature verification and decryption phase involves the receiver verifying the signature using the sender's identity information and decrypting the message using their own private key to obtain the original message. The symbols and explanations used in this invention are shown in Table 1. Table 1. Symbol Explanation

[0022] 1. System Setup Phase: This invention employs identity-based digital signature encryption (IBS-IBE), starting with a key generation center in an IoT environment. The system will be established and its public parameters will be published.

[0023] Step 1: First, the key generation center Generate bilinear parameters ,in yes Additive cyclic group of order, yes Multiplicative cyclic group of order, It is a group The two generators, It is a bilinear mapping.

[0024] Step 2: Choose two hash functions . , , The length of the message.

[0025] Here, {0,1}* represents a binary sequence of arbitrary length, that is, any numerical information. For example, user or device identification information (ID), such as a device number "Device_12345", or a user's email address, will be converted into binary information by the computer for processing. Let q represent a set of integers greater than 0 and less than q; q is a large prime number chosen in Step 1. Hash function Output a positive integer within a specified range.

[0026] It is a one-way hash function, the input is a value in group G2, and the output is... The value of is similar to a linear function in one variable. G2 is the q-order multiplicative cyclic group defined in Step 1. The elements in this group can be viewed as a complex "shared key intermediate value" generated through the bilinear mapping e. It may be very long and not suitable for direct use as an encryption key. This represents a binary sequence of length n bits. n is the length of the message to be encrypted. For example, if the message is 128 bits, then the output will be 128 bits.

[0027] Step 3: Choose a random number As the master key And calculate the public key. .

[0028] Step 4: Release System Common Parameters .

[0029] 2. Key Extraction Stage: The registration and key extraction phase is the second phase of the scheme, where any user... and equipment To connect to an IoT system, you must first send a key to the key generation center via a smart device. Submitting a registration request and registering using one's own identity information involves key extraction by both the user and the device. This process takes place over a secure channel. The key generation center calculates the corresponding private key and sends it to the user and device for subsequent signing and verification, thus facilitating identity authentication. The user and device key extraction process is as follows: Figure 3 As shown. Users refer to terminals such as iPads, computers, and mobile phones. Devices include, for example, monitoring equipment, smart home appliances, smart door locks, PLC controllers, vehicle terminals, etc.

[0030] In an Internet of Things (IoT) system, the information exchange parties are either users and devices or devices and devices. Therefore, both users and devices are communication nodes in the system, and the registration process for both roles is the same. Taking device registration as an example: Step 1: First, the equipment As a communication node in the system, it uses its own identity information after the system is established. To the key generation center Submit a registration request.

[0031] Step 2: Key Generation Center Received equipment After the registration request, based on the device information ,calculate Then use the system master key Private key corresponding to computing device After generating a key for this device node, Will and system parameters Send to device via secure channel .

[0032] Once the device registration process is complete, the device will connect to the system and publicly display its identity information.

[0033] Taking user registration as an example: Step 1: First, the user As a communication node in the system, it uses its own identity information after the system is established. To the key generation center Submit a registration request.

[0034] Step 2: Key Generation Center Received from user After the registration request, based on the user's identity information ,calculate Then use the system master key Calculate the user's private key After generating a key for this user, Will and system parameters Sent to the user via a secure channel .

[0035] 3. Signature Encryption Stage (Sign): In IoT systems, information exchange occurs between users and devices, or between devices. There are application scenarios where users send specific requests to devices, and there are also actions where a device sends instructions to other devices to execute operations. Therefore, we consider both user-device authentication processes and device-to-device authentication processes. As communication nodes in the system, the two processes maintain consistent interaction at this stage. This embodiment describes the user-device authentication stage in detail.

[0036] The main operation performed in the signing process is to generate a signature for the message. This process includes encryption and signing operations, which are executed by the signer. In this stage, the signer uses the private key and system public parameters to encrypt and sign the message to be signed, and then sends it to the recipient.

[0037] When users Requires logging into the system to access specific devices Send message In this case, it is necessary to use one's own private key and calculate the ciphertext and signature value using random numbers, timestamps, hash functions, etc., and then send the specific message to a specific device. .

[0038] Step 1: First, the user Select a one-time random number .

[0039] Step 2: User calculate , Subsequently, regarding the message Encryption is used to protect confidentiality, thus obtaining... Calculate the ciphertext hash value of the message. After completing the hashing of the message, the user... Perform data signing .

[0040] in,

[0041]

[0042]

[0043]

[0044] Step 3: User Get current timestamp This system synchronizes with the time source at all times to ensure compliance with the time accuracy standards of the National Time Service Center. Finally, the calculated encrypted message signature and timestamp are sent to the target device. ,user Send request information: { }

[0045] 4. Verification and Decryption Stage: The main operation performed during the signature verification process is to verify the message signature. This stage is mainly performed by the verifier. The verifier decrypts the message and ciphertext data that has been signed by the signer using the signer's information and public parameters to verify the legality of the signature and determine whether the verification is successful.

[0046] equipment Verify User The message, along with its own parameters, is used for authentication response. User Upon receiving the authentication message, the signature information is calculated and verification is performed. Simultaneously, the message... Decryption is performed to ensure security. The signing and verification process is as follows: Figure 4 As shown.

[0047] Step 1: Equipment Upon receiving a message from the sender, first calculate... , Check at the current time. Whether it is valid or not, due to Since the time difference is an arbitrarily small positive number, we can determine whether the timestamp is within a reliable range by checking the time difference. Then, we can verify this using common parameters. Check if the equation is true. If it is false, terminate the session; otherwise, authenticate the user. Continue message retrieval.

[0048] The derivation process is as follows:

[0049]

[0050]

[0051]

[0052]

[0053] Step 2: Equipment To decrypt a message using its own private key, first calculate... , obtain intermediate variables Then, use ciphertext Calculate message value .

[0054] The embodiments of the present invention are analyzed from the perspectives of safety and efficiency as follows: 1. Security Analysis (1) Provable Security: Assuming the known CDH problem is difficult, the proposed solution is provably secure under the stochastic oracle model. Adversary A and challenger C are introduced. Adversary A chooses a target identity. It is then sent to challenger C. C executes the system setup process in the protocol to generate the master key. Given a series of system parameters, and return these parameters to A; adversary A adaptively issues hash queries, private key extraction queries, and signature queries to challenger C, and receives responses from C. If adversary A has a non-negligible advantage to win the game described above, then a challenger C can be constructed to solve the CDH problem. The probability that C solves the CDH problem through secure proof is:

[0055] in This indicates that A did the following in the above game: Number of queries. This represents the probability of challenger C's success; Indicates the first event, identity Hash lookup successful; This indicates the second event: adversary A successfully forged two legitimate data signatures. Indicates in The following occurred The conditional probability of occurrence; Indicates an event The probability of occurrence; Let be any small positive number.

[0056] because It is an advantage that cannot be ignored. Since C is polynomially bounded, we can conclude that it can solve the CDH problem with a non-negligible advantage. Because the CDH problem is a well-known difficult problem, and the challenge contradicts the insolvability of difficult problems in reality, the proposed identity-based signature-based scheme is secure under the random oracle model.

[0057] (2) Anti-replay attack: The solution design introduces timestamps. and utilize The restrictions effectively prevent replay attacks, avoiding situations where attackers issue duplicate commands after a user issues a command to a device or tasks are issued between devices, thus ensuring security.

[0058] 2. Efficiency Analysis Unlike the communication process between smart devices in most IoT systems, this solution does not frequently access the CA certification center during information exchange when users communicate with devices or between devices, thus saving a significant amount of communication costs.

[0059] Furthermore, traditional digital signatures (such as RSA and SM2) rely on "Public Key Infrastructure (PKI)," which requires a CA to issue digital certificates for the user's public key. This presents complex management issues such as certificate storage, verification, and revocation, which are difficult to adapt to resource-constrained scenarios such as the Internet of Things and mobile devices. In contrast, the digital signature encryption IBS-IBE scheme simplifies the key management process by adopting the design of "identity as public key."

[0060] This invention proposes an identity-based digital signature encryption scheme (IBS-IBE) for IoT environments, providing authentication and ensuring data integrity and confidentiality. It eliminates point-to-point hashing operations, removing the need for certificate verification and other computational processes required in PKI, resulting in lower computational costs. It is suitable for various terminals in IoT environments, reducing computational expenses. It eliminates the need for digital certificates in the PKI system, Certificate Authority (CA) centers, and certificate issuance and retrieval, making it simple to use and easy to deploy. A rich policy control mechanism integrates identity authentication and data confidentiality protection. Timestamps are used to prevent replay attacks. The security of the scheme is proven under a random oracle model. Therefore, the proposed scheme uses IBS-IBE to simplify key management through identity identification, reducing communication overhead and deployment costs, while ensuring identity authentication and data security during communication, making it suitable for IoT environments.

[0061] Based on the same inventive concept, this invention also provides an Internet of Things (IoT) security system for implementing the methods described in the above embodiments, with reference to... Figure 2 As shown, it includes: smart terminal devices, users, and the key generation center KGC; Among them, the Key Generation Center (KGC) is used to execute the system setup and key extraction steps; Smart terminal devices and users are used to perform signature encryption and signature verification / decryption steps.

[0062] This system can effectively reduce communication overhead and deployment costs, and ensure identity authentication and data security during the communication process.

[0063] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0064] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An identity-based digital signature encryption method in an Internet of Things (IoT) environment, characterized in that, Includes the following steps: System setup steps: The Key Generation Center (KGC) generates system parameters, including bilinear mapping parameters, hash functions, and master keys, and publishes the public parameters; Key extraction steps: Receive registration information submitted by the user or device using their own identity information to KGC; KGC calculates and distributes the corresponding private key based on the identity information. Signature encryption steps: The sender encrypts the message using the recipient's identity information and signs the message with its own private key; Signature verification and decryption steps: The recipient uses the sender's identity information to verify the signature's legitimacy and then uses their own private key to decrypt the message.

2. The method according to claim 1, characterized in that, The system establishment steps include: (1) Key generation center KGC generates bilinear parameters ,in yes Additive cyclic group of order, yes Multiplicative cyclic group of order, It is a group The two generators, It is a bilinear mapping, representing ; (2) KGC selects two hash functions ; , , The length of the message; (3) KGC selects a random number As the master key And calculate the public key. ; (4) Common parameters of KGC publishing system .

3. The method according to claim 2, characterized in that, The key extraction step includes: (1) KGC receives registration requests submitted by users or devices using their own identity information ID; (2) KGC calculates R based on the identity information ID. (ID), and use the master key s to generate the private key S=s·R·Q; send {R,S} and system parameters to the corresponding user or device through a secure channel.

4. The method according to claim 3, characterized in that, The signature encryption steps include: (1) The sender selects a random number r; (2) The sender calculates the ciphertext C=r·P and the encryption key. encrypt message M to obtain and generate a signature. ,in ; (3) The sender obtains the current timestamp The calculated ciphertext, the encrypted ciphertext of the message, the ciphertext signature, and the timestamp are sent to the corresponding recipient.

5. The method according to claim 4, characterized in that, The signature verification and decryption steps include: (1) Receiver calculation , Check at the current time. Whether it is valid, Let be any small positive number; if true, verify the equation. Are they equal? (2) If they are equal, then decrypt the message. ,in .

6. An Internet of Things (IoT) security system for implementing the method as described in any one of claims 1-5, characterized in that, include: Intelligent terminal devices, users, and key generation center (KGC); The key generation center (KGC) is used to perform the system establishment steps and key extraction steps. The smart terminal device and the user are used to perform the signature encryption step and the signature verification and decryption step.

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