Electronic device for selecting an encryption key based on the amount of information in the data to be encrypted, and operating method for an electronic device

Description

[Technical Field]

[0001] Various embodiments of the disclosure relate to an electronic device and a method of operating an electronic device, and more particularly, to a technology for selecting a key to be used for encryption on the basis of an amount of information of data to be encrypted and encrypting the data using the selected key.[Background Art]

[0002] Various electronic devices such as smart phones, tablet Personal Computers (PCs), Portable Multimedia Players (PMPs), Personal Digital Assistants (PDAs), laptop PCs, and wearable devices have been distributed.

[0003] Various electronic devices may demand user authentication in order to provide a variety of functions which the electronic device can provide. The electronic device may receive information for user authentication input by a user and compare the information for the user authentication with information configured by the user, so as to perform the user authentication. The electronic device may provide a variety of functions which the electronic device can provide according to the result of the user authentication.

[0004] For example, the electronic device may perform user authentication through an operation of receiving a password input by the user to perform user authentication and comparing the input password with a password conventionally configured by the user. The password input by the user may be data implemented by a combination of letters / numbers or data implemented by user's biometric information (for example, a user's fingerprint, a user's iris, or user's face information). A plurality of modules (for example, various modules including a module for file encryption or a module for switching to an unlocking mode) demanding a password may be implemented in an electronic device, and the plurality of modules may receive a password input by the user and transmit the received password to a password processing module in order to verify the password. The password processing module may transmit the result of verifying the received password to a plurality of modules, and the plurality of modules may determine whether to activate various functions on the basis of the verification result. US2007220616A1 relates to portable storage. The storage includes a plurality of authentication modules that perform mutual authentication using different mutual authentication algorithms; a control module that controls the authentication modules so that any one among the authentication modules can perform mutual authentication work with a host device through the DRM system identifier extracted from an authentication-request message received from the host device; and an object-management module that protects communication with the host device using a generated session key as a result of the mutual authentication. US2017163414A1 relates to a method of encrypting data transmitted from a first device to a second device, performed by using an Advanced Encryption Standard (AES) encryption algorithm, includes obtaining size information of an encryption key and size information of data that is to be encrypted and includes a plurality of bits; encrypting a first bit group, which is at least one bit corresponding to a size of the encryption key, among the plurality of bits, by using the encryption key; selecting a third bit group, which is at least one bit of the encrypted first bit group based on size information of the encryption key and a size of a second bit group including bits that are different from the first bit group among the plurality of bits; and encrypting the second bit group and the selected third bit group by using the encryption key. US2009103732A1 relates to a method for personalizing a secure processor in a NFC system to execute a secure application, comprising steps of obtaining by a server identification data of a user memorized in a secure storage medium, personalization data corresponding to the user identification data, and identification data of a NFC system of the user, comprising an encryption key of the secure processor, encrypting by the server personalization data using the encryption key, transmitting to the NFC system encrypted personalization data, receiving by the secure processor encrypted personalization data, deciphering personalization data, and memorizing in a secured way personalization data by the secure processor. US2004109569 relates to protected content distribution that is accomplished by a first entity generating a set of asymmetric key pairs, creating a plurality of sets of private keys by selecting a combination of private keys from the set of asymmetric key pairs for each created set, and distributing the sets of private keys to playback devices. A second entity produces protected content including encrypted content and a public key media key block, encrypts a symmetric content key with each public key in the set of asymmetric key pairs to form the public key media key block and encrypts a content title with the symmetric content key to form the encrypted content. A playback device stores one set of private keys, receives the protected content, and decrypts and plays the content title stored in the protected content when a selected one of the set of private keys stored by the playback device successfully decrypts the encrypted symmetric content key stored in the public key media key block of the received protected content.[Disclosure of Invention][Technical Problem]

[0005] In a process in which a password input by a user is transferred to a password processing module for processing a password, the password may be copied several times in the transferring process and the copied password may exist in a partial area of a memory. The password existing in the partial area of the memory may be exposed to an attacker who acquires authority for accessing the memory, and thus security may be compromised.[Solution to Problem]

[0006] The present invention is set out in the independent claims, with some optional features set out in the claims dependent thereto. An electronic device according to various embodiments of the disclosure includes: a user interface; a processor operatively connected to the user interface; and a memory operatively connected to the processor and including a normal area and a secure area, wherein the memory configured to store a plurality of keys for encrypting data corresponding to a user input and store instructions causing the processor, when executed, receive the data through the user interface, nontemporarily store the received data in the normal area, identify an information quantity of the stored data, select at least one of the plurality of keys stored in the memory, based on at least a portion of the identified information quantity, encrypt the data using the selected key, and transmit the encrypted data and information indicating the selected key to the secure area which demands access authority.

[0007] A method of operating an electronic device according to various embodiments of the disclosure includes: receiving data corresponding to a user input through a user interface; nontemporarily storing the received data in a normal area of a memory; identifying an information quantity of the stored data; selecting one of a plurality of keys stored in the memory, based on at least a portion of the information quantity of the data; encrypting the data by using the selected key; and transmitting the encrypted data and information indicating the selected key to a secure area which demands access authority.[Advantageous Effects of Invention]

[0008] An electronic device and a method of operating an electronic device according to various embodiments of the disclosure can improve security of the electronic device by encrypting input data, transmitting the encrypted data to a secure area, and deleting data existing in a normal area.

[0009] An electronic device and a method of operating an electronic device according to various embodiments of the disclosure can improve security of data since encrypted data is exposed even though data transmitted / received within the electronic device is exposed to an attacker.

[0010] An electronic device and a method of operating an electronic device according to various embodiments of the disclosure can select a size of a key to be used for encryption of data on the basis of an information quantity of the input data, so as to prevent decline of encryption speed generated by encryption of data having a small information quantity of data using a key having an excessively large size and increase the encryption speed.[Brief Description of Drawings]

[0011] FIG. 1 is a block diagram of an electronic device according to various embodiments of the disclosure; FIG. 2 is a block diagram illustrating a program according to various embodiments; FIG. 3 is a block diagram of an electronic device according to various embodiments of the disclosure; FIG. 4 is a block diagram illustrating a normal area and a secure area in an electronic device according to various embodiments; FIG. 5 is a flowchart illustrating the operation in a method of operating an electronic device according to various embodiments of the disclosure; and FIG. 6 is a flowchart illustrating the operation in a method of operating an electronic device according to various embodiments of the disclosure.

[0012] In connection with description of drawings, the same or similar reference numerals may be used for the same or similar elements.[Mode for Carrying Out the Invention]

[0013] FIG. 1 is a block diagram illustrating an electronic device 101 in a network environment 100 according to various embodiments. Referring to FIG. 1, the electronic device 101 in the network environment 100 may communicate with an electronic device 102 via a first network 198 (e.g., a short-range wireless communication network), or an electronic device 104 or a server 108 via a second network 199 (e.g., a long-range wireless communication network). According to an embodiment, the electronic device 101 may communicate with the electronic device 104 via the server 108. According to an embodiment, the electronic device 101 may include a processor 120, memory 130, an input device 150, a sound output device 155, a display device 160, an audio module 170, a sensor module 176, an interface 177, a haptic module 179, a camera module 180, a power management module 188, a battery 189, a communication module 190, a subscriber identification module(SIM) 196, or an antenna module 197. In some embodiments, at least one (e.g., the display device 160 or the camera module 180) of the components may be omitted from the electronic device 101, or one or more other components may be added in the electronic device 101. In some embodiments, some of the components may be implemented as single integrated circuitry. For example, the sensor module 176 (e.g., a fingerprint sensor, an iris sensor, or an illuminance sensor) may be implemented as embedded in the display device 160 (e.g., a display).

[0014] The processor 120 may execute, for example, software (e.g., a program 140) to control at least one other component (e.g., a hardware or software component) of the electronic device 101 coupled with the processor 120, and may perform various data processing or computation. According to one embodiment, as at least part of the data processing or computation, the processor 120 may load a command or data received from another component (e.g., the sensor module 176 or the communication module 190) in volatile memory 132, process the command or the data stored in the volatile memory 132, and store resulting data in non-volatile memory 134. According to an embodiment, the processor 120 may include a main processor 121 (e.g., a central processing unit (CPU) or an application processor (AP)), and an auxiliary processor 123 (e.g., a graphics processing unit (GPU), an image signal processor (ISP), a sensor hub processor, or a communication processor (CP)) that is operable independently from, or in conjunction with, the main processor 121. Additionally or alternatively, the auxiliary processor 123 may be adapted to consume less power than the main processor 121, or to be specific to a specified function. The auxiliary processor 123 may be implemented as separate from, or as part of the main processor 121.

[0015] The auxiliary processor 123 may control at least some of functions or states related to at least one component (e.g., the display device 160, the sensor module 176, or the communication module 190) among the components of the electronic device 101, instead of the main processor 121 while the main processor 121 is in an inactive (e.g., sleep) state, or together with the main processor 121 while the main processor 121 is in an active state (e.g., executing an application). According to an embodiment, the auxiliary processor 123 (e.g., an image signal processor or a communication processor) may be implemented as part of another component (e.g., the camera module 180 or the communication module 190) functionally related to the auxiliary processor 123.

[0016] The memory 130 may store various data used by at least one component (e.g., the processor 120 or the sensor module 176) of the electronic device 101. The various data may include, for example, software (e.g., the program 140) and input data or output data for a command related thererto. The memory 130 may include the volatile memory 132 or the non-volatile memory 134.

[0017] The program 140 may be stored in the memory 130 as software, and may include, for example, an operating system (OS) 142, middleware 144, or an application 146.

[0018] The input device 150 may receive a command or data to be used by other component (e.g., the processor 120) of the electronic device 101, from the outside (e.g., a user) of the electronic device 101. The input device 150 may include, for example, a microphone, a mouse, a keyboard, or a digital pen (e.g., a stylus pen).

[0019] The sound output device 155 may output sound signals to the outside of the electronic device 101. The sound output device 155 may include, for example, a speaker or a receiver. The speaker may be used for general purposes, such as playing multimedia or playing record, and the receiver may be used for an incoming calls. According to an embodiment, the receiver may be implemented as separate from, or as part of the speaker.

[0020] The display device 160 may visually provide information to the outside (e.g., a user) of the electronic device 101. The display device 160 may include, for example, a display, a hologram device, or a projector and control circuitry to control a corresponding one of the display, hologram device, and projector. According to an embodiment, the display device 160 may include touch circuitry adapted to detect a touch, or sensor circuitry (e.g., a pressure sensor) adapted to measure the intensity of force incurred by the touch.

[0021] The audio module 170 may convert a sound into an electrical signal and vice versa. According to an embodiment, the audio module 170 may obtain the sound via the input device 150, or output the sound via the sound output device 155 or a headphone of an external electronic device (e.g., an electronic device 102) directly (e.g., wiredly) or wirelessly coupled with the electronic device 101.

[0022] The sensor module 176 may detect an operational state (e.g., power or temperature) of the electronic device 101 or an environmental state (e.g., a state of a user) external to the electronic device 101, and then generate an electrical signal or data value corresponding to the detected state. According to an embodiment, the sensor module 176 may include, for example, a gesture sensor, a gyro sensor, an atmospheric pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an infrared (IR) sensor, a biometric sensor, a temperature sensor, a humidity sensor, or an illuminance sensor.

[0023] The interface 177 may support one or more specified protocols to be used for the electronic device 101 to be coupled with the external electronic device (e.g., the electronic device 102) directly (e.g., wiredly) or wirelessly. According to an embodiment, the interface 177 may include, for example, a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, a secure digital (SD) card interface, or an audio interface.

[0024] A connecting terminal 178 may include a connector via which the electronic device 101 may be physically connected with the external electronic device (e.g., the electronic device 102). According to an embodiment, the connecting terminal 178 may include, for example, a HDMI connector, a USB connector, a SD card connector, or an audio connector (e.g., a headphone connector).

[0025] The haptic module 179 may convert an electrical signal into a mechanical stimulus (e.g., a vibration or a movement) or electrical stimulus which may be recognized by a user via his tactile sensation or kinesthetic sensation. According to an embodiment, the haptic module 179 may include, for example, a motor, a piezoelectric element, or an electric stimulator.

[0026] The camera module 180 may capture a still image or moving images. According to an embodiment, the camera module 180 may include one or more lenses, image sensors, image signal processors, or flashes.

[0027] The power management module 188 may manage power supplied to the electronic device 101. According to one embodiment, the power management module 188 may be implemented as at least part of, for example, a power management integrated circuit (PMIC).

[0028] The battery 189 may supply power to at least one component of the electronic device 101. According to an embodiment, the battery 189 may include, for example, a primary cell which is not rechargeable, a secondary cell which is rechargeable, or a fuel cell.

[0029] The communication module 190 may support establishing a direct (e.g., wired) communication channel or a wireless communication channel between the electronic device 101 and the external electronic device (e.g., the electronic device 102, the electronic device 104, or the server 108) and performing communication via the established communication channel. The communication module 190 may include one or more communication processors that are operable independently from the processor 120 (e.g., the application processor (AP)) and supports a direct (e.g., wired) communication or a wireless communication. According to an embodiment, the communication module 190 may include a wireless communication module 192 (e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module 194 (e.g., a local area network (LAN) communication module or a power line communication (PLC) module). A corresponding one of these communication modules may communicate with the external electronic device via the first network 198 (e.g., a short-range communication network, such as BluetoothTM, wireless-fidelity (Wi-Fi) direct, or infrared data association (IrDA)) or the second network 199 (e.g., a long-range communication network, such as a cellular network, the Internet, or a computer network (e.g., LAN or wide area network (WAN)). These various types of communication modules may be implemented as a single component (e.g., a single chip), or may be implemented as multi components (e.g., multi chips) separate from each other. The wireless communication module 192 may identify and authenticate the electronic device 101 in a communication network, such as the first network 198 or the second network 199, using subscriber information (e.g., international mobile subscriber identity (IMSI)) stored in the subscriber identification module 196.

[0030] The antenna module 197 may transmit or receive a signal or power to or from the outside (e.g., the external electronic device) of the electronic device 101. According to an embodiment, the antenna module 197 may include an antenna including a radiating element composed of a conductive material or a conductive pattern formed in or on a substrate (e.g., PCB). According to an embodiment, the antenna module 197 may include a plurality of antennas. In such a case, at least one antenna appropriate for a communication scheme used in the communication network, such as the first network 198 or the second network 199, may be selected, for example, by the communication module 190 (e.g., the wireless communication module 192) from the plurality of antennas. The signal or the power may then be transmitted or received between the communication module 190 and the external electronic device via the selected at least one antenna. According to an embodiment, another component (e.g., a radio frequency integrated circuit (RFIC)) other than the radiating element may be additionally formed as part of the antenna module 197.

[0031] At least some of the above-described components may be coupled mutually and communicate signals (e.g., commands or data) therebetween via an inter-peripheral communication scheme (e.g., a bus, general purpose input and output (GPIO), serial peripheral interface (SPI), or mobile industry processor interface (MIPI)).

[0032] According to an embodiment, commands or data may be transmitted or received between the electronic device 101 and the external electronic device 104 via the server 108 coupled with the second network 199. Each of the electronic devices 102 and 104 may be a device of a same type as, or a different type, from the electronic device 101. According to an embodiment, all or some of operations to be executed at the electronic device 101 may be executed at one or more of the external electronic devices 102, 104, or 108. For example, if the electronic device 101 should perform a function or a service automatically, or in response to a request from a user or another device, the electronic device 101, instead of, or in addition to, executing the function or the service, may request the one or more external electronic devices to perform at least part of the function or the service. The one or more external electronic devices receiving the request may perform the at least part of the function or the service requested, or an additional function or an additional service related to the request, and transfer an outcome of the performing to the electronic device 101. The electronic device 101 may provide the outcome, with or without further processing of the outcome, as at least part of a reply to the request. To that end, a cloud computing, distributed computing, or client-server computing technology may be used, for example.

[0033] FIG. 2 is a block diagram 200 illustrating the program 140 according to various embodiments. According to an embodiment, the program 140 may include an operating system (OS) 142 to control one or more resources of the electronic device 101, middleware 144, or an application 146 executable in the OS 142. The OS 142 may include, for example, AndroidTM, iOSTM, WindowsTM, SymbianTM, TizenTM, or BadaTM. At least part of the program 140, for example, may be preloaded on the electronic device 101 during manufacture, or may be downloaded from or updated by an external electronic device (e.g., the electronic device 102 or 104, or the server 108) during use by a user.

[0034] The OS 142 may control management (e.g., allocating or deallocation) of one or more system resources (e.g., process, memory, or power source) of the electronic device 101. The OS 142, additionally or alternatively, may include one or more driver programs to drive other hardware devices of the electronic device 101, for example, the input device 150, the sound output device 155, the display device 160, the audio module 170, the sensor module 176, the interface 177, the haptic module 179, the camera module 180, the power management module 188, the battery 189, the communication module 190, the subscriber identification module 196, or the antenna module 197.

[0035] The middleware 144 may provide various functions to the application 146 such that a function or information provided from one or more resources of the electronic device 101 may be used by the application 146. The middleware 144 may include, for example, an application manager 201, a window manager 203, a multimedia manager 205, a resource manager 207, a power manager 209, a database manager 211, a package manager 213, a connectivity manager 215, a notification manager 217, a location manager 219, a graphic manager 221, a security manager 223, a telephony manager 225, or a voice recognition manager 227.

[0036] The application manager 201, for example, may manage the life cycle of the application 146. The window manager 203, for example, may manage one or more graphical user interface (GUI) resources that are used on a screen. The multimedia manager 205, for example, may identify one or more formats to be used to play media files, and may encode or decode a corresponding one of the media files using a codec appropriate for a corresponding format selected from the one or more formats. The resource manager 207, for example, may manage the source code of the application 146 or a memory space of the memory 130.The power manager 209, for example, may manage the capacity, temperature, or power of the battery 189, and determine or provide related information to be used for the operation of the electronic device 101 based at least in part on corresponding information of the capacity, temperature, or power of the battery 189. According to an embodiment, the power manager 209 may interwork with a basic input / output system (BIOS) (not shown) of the electronic device 101.

[0037] The database manager 211, for example, may generate, search, or change a database to be used by the application 146. The package manager 213, for example, may manage installation or update of an application that is distributed in the form of a package file. The connectivity manager 215, for example, may manage a wireless connection or a direct connection between the electronic device 101 and the external electronic device. The notification manager 217, for example, may provide a function to notify a user of an occurrence of a specified event (e.g., an incoming call, message, or alert). The location manager 219, for example, may manage locational information on the electronic device 101. The graphic manager 221, for example, may manage one or more graphic effects to be offered to a user or a user interface related to the one or more graphic effects.

[0038] The security manager 223, for example, may provide system security or user authentication. The telephony manager 225, for example, may manage a voice call function or a video call function provided by the electronic device 101. The voice recognition manager 227, for example, may transmit a user's voice data to the server 108, and receive, from the server 108, a command corresponding to a function to be executed on the electronic device 101 based at least in part on the voice data, or text data converted based at least in part on the voice data. According to an embodiment, the middleware 244 may dynamically delete some existing components or add new components. According to an embodiment, at least part of the middleware 144 may be included as part of the OS 142 or may be implemented as another software separate from the OS 142.

[0039] The application 146 may include, for example, a home 251, dialer 253, short message service (SMS) / multimedia messaging service (MMS) 255, instant message (IM) 257, browser 259, camera 261, alarm 263, contact 265, voice recognition 267, email 269, calendar 271, media player 273, album 275, watch 277, health 279 (e.g., for measuring the degree of workout or biometric information, such as blood sugar), or environmental information 281 (e.g., for measuring air pressure, humidity, or temperature information) application. According to an embodiment, the application 146 may further include an information exchanging application (not shown) that is capable of supporting information exchange between the electronic device 101 and the external electronic device. The information exchange application, for example, may include a notification relay application adapted to transfer designated information (e.g., a call, message, or alert) to the external electronic device or a device management application adapted to manage the external electronic device. The notification relay application may transfer notification information corresponding to an occurrence of a specified event (e.g., receipt of an email) at another application (e.g., the email application 269) of the electronic device 101 to the external electronic device. Additionally or alternatively, the notification relay application may receive notification information from the external electronic device and provide the notification information to a user of the electronic device 101.

[0040] The device management application may control the power (e.g., turn-on or turn-off) or the function (e.g., adjustment of brightness, resolution, or focus) of the external electronic device or some component thereof (e.g., a display device or a camera module of the external electronic device). The device management application, additionally or alternatively, may support installation, delete, or update of an application running on the external electronic device.

[0041] FIG. 3 is a block diagram of an electronic device 300 according to various embodiments of the disclosure.

[0042] The electronic device 300 according to various embodiments of the disclosure (for example, the electronic device 101 of FIG. 1) may include a user interface 310, a memory 320 (for example, the memory 130 of FIG. 1), and a processor 330 (for example, the processor 120 of FIG. 1).

[0043] According to various embodiments of the disclosure, the user interface 310 may receive a user input corresponding to data to be encrypted on the basis of the control of the processor 330. The user input may be a user input of inputting a password for various functions which can be provided by the electronic device 300. For example, the user input may be a user input of inputting a password for switching a locked state in which at least some functions are deactivated to an unlocked state in which at least some functions are activated. The password may be data implemented by a combination of letters / numbers, data implemented by pattern information in various forms which can be input into a display, data implemented by user's biometric information (for example, various pieces of biometric information including a user's fingerprint, iris, or face), or data in various type which can be implemented in the future.

[0044] According to various embodiments of the disclosure, the user interface 310 may be implemented in various forms for receiving a user input. For example, the user interface 310 may be implemented as a display. The display may display various screens on the basis of the control of the processor 330 and receive a user input on the display. The display may receive a user input corresponding to data to be encrypted. The display may display a screen for inputting a user input on the basis of the control of the processor 330, receive the user input in the state in which the screen is displayed, and transmit data corresponding to the user input to the processor 330.

[0045] In another example, the user interface 310 may be a sensor module capable of acquiring user's biometric information. The user interface 310 may be implemented in the form of a fingerprint recognition sensor capable of acquiring user's fingerprint information in various types (for example, ultrasonic type or capacitive type), an infrared camera capable of acquiring user's iris information, and a Time of Flight (ToF) camera capable of acquiring user's face information.

[0046] According to various embodiments of the disclosure, the memory 320 may temporarily or nontemporarily store various pieces of data. The memory 320 may transmit the temporarily or nontemporarily stored data to the processor 330. The memory 320 may store one or more keys which can be used for encryption of data corresponding to a user input and transmit the keys stored in the memory 320 to the processor 330 in response to a request from the processor 330.

[0047] According to various embodiments of the disclosure, the processor 330 may encrypt the data corresponding to the user input and transmit the encrypted data to a secure area. The data corresponding to the user input may be temporarily stored in a normal area. The secure area may be an area which can be accessed in the case in which there is specific authority (for example, authority of access to the secure area or authority of correction of data stored in the secure area). The normal area may be an area which can be accessed without any specific authority. The normal area and the secure area can be implemented in the processor 330 or the memory 320.

[0048] According to various embodiments of the disclosure, the processor 330 may encrypt the data corresponding to the user input through various encryption schemes (for example, various encryption schemes including an RSA encryption algorithm and an Elliptic Curve Integrated Encryption Scheme (ECIES) algorithm).

[0049] According to various embodiments of the disclosure, the processor 330 may differently select a key to be used for encryption of the input data according to an information quantity of the input data. The information quantity of the data may be entropy of data which is an actual security secret value of the input data (value indicating a security strength according to the length of data).

[0050] For example, when it is assumed that the input data (for example, 01234) is data of a five-digit number including only numbers, the total number of pieces of data which can be implemented in every digit is 10, that is, 0 to 9, and thus the information quantity of the input data may be 10 5< . In another example, when it is assumed that the input data (for example, AaBbC) is data of a five-digit number including only letters, the total number of data which can be implemented in one digit is 52, that is, A to Z and a to z, and thus the information quantity of the input data may be 52 5< . In another example, when it is assumed that the input data (for example, aAbC45) is data of a six-digit number including letters and numbers, the total number of data which can be implemented in one digit is 62, that is, 0 to 9, a to z, and A to Z, and thus the information quantity of the input data may be 62 6< . In another example, when it is assumed that the input data (for example, AaB4@) is data of a five-digit number including letters, numbers, and special characters, the total number of data which can be implemented in one digit is 80, that is, 0 to 9, a to z, A to Z, and the number of special characters which can be input (assumed as 16), and thus the information quantity of the input data may be 80 5< .

[0051] According to various embodiments, the example of calculating the information quantity of the data is only one embodiment, and the processor 330 may identify the information quantity of the data through various schemes. The processor 330 may identify the information quantity of the data through various schemes according to attributes of the input data (for example, attributes indicating whether the input data corresponds to a data type implemented by a combination of letters / numbers or a data type implemented by user's biometric information).

[0052] According to various embodiments of the disclosure, the processor 330 may identify types of elements (for example, letter, number, or special character) included in the input data and the number of elements included in the data, and identify the information quantity of the data on the basis of the types and the number of elements.

[0053] According to various embodiments of the disclosure, the processor 330 may select one of a plurality of keys stored in the memory 320 on the basis of the identified information quantity of the data.

[0054] According to various embodiments of the disclosure, the plurality of keys stored in the memory 320 may have different sizes, and the memory 320 may store data to which a range of the information quantity of the data and information indicating the key are mapped to use different keys depending on the information quantity of the data. The information indicating the key may be information (key size data) indicating the size of the key or information (index) indicating the key.

[0055] According to various embodiments of the disclosure, the memory 320 may store data to which the range of the information quantity of the data and the information indicating key are mapped to use a key having a larger size as the information quantity of the data increases. Alternatively, the memory 320 may store data to which the range of the information quantity of the data and the information indicating key are mapped to use a key having a smaller size as the information quantity of the data decreases. The data to which the range of the information quantity and the information indicating the key are mapped may be implemented in various forms. For example, the memory 320 may store data to which the range of the information quantity of the data and the information indicating the key are mapped in the form of a table as shown in [Table 1] or [Table 2] below. [Table 1]Information quantity (X)Key sizeX<52 4< 51252 4< <X<80 6< 1024......80 6< <X<80 16< 4096 [Table 2] Information quantity (X)Key indexX<52 4< 152 4< <X<80 6< 2......80 6< <X<80 16< N

[0056] Referring to [Table 1], as the information quantity (X) of input data increases, the size of a key used for encryption of the input data may increase. Alternatively, as the information quantity (X) of input data decreases, the size of a key used for encryption of the input data may decrease. The size of the key may be the number of bits of the key. The memory 320 may store data to which a range of the information quantity and information indicating a key to be used for encryption of data included in the range of the information quantity are mapped in various forms (for example, the table shown in [Table 1]). The data to which the range of the information quantity and the information indicating the key to be used for encryption of the data included in the range of the information quantity are mapped may be stored in another area which can be accessed in all of the normal area, the secure area, or the normal area and the secure area.

[0057] According to various embodiments of the disclosure, the processor 330 may identify the information quantity of the input data and identify the range of the information quantity to which the information quantity of the input data belongs. The processor 330 may select a key to be used for encryption of the input data among the plurality of keys on the basis of the range of the information quantity and the information indicating the key to be used for encryption of the data included in the range of the information quantity. According to various embodiments of the disclosure, the plurality of keys may be stored in the secure area and the normal area. According to various embodiments of the disclosure, when a password is configured, the processor 330 may identify the information quantity of the password and identify a range of the information quantity to which the information quantity of the input data belongs. The processor 330 may select a key to be used for encryption of the input data among the plurality of keys on the basis of the range of the information quantity and the information indicating the key to be used for encryption of the data included in the range of the information quantity. After receiving a user input, the processor 330 may encrypt data corresponding to the user input using a preselected key without identifying the information quantity of the data corresponding to the user input.

[0058] According to various embodiments of the disclosure, the processor 330 may encrypt the input data on the basis of the selected key. Encryption of the input data may be performed in the normal area on the basis of the control of the processor 330.

[0059] According to various embodiments of the disclosure, the processor 330 may identify a certificate corresponding to each of the plurality of keys stored in the normal area. The certificate may be data for verifying reliability of the secure area or the key. The processor 330 may determine whether to encrypt the input data and whether to transmit the encrypted data to the secure area on the basis of the identification result of the certificate.

[0060] According to various embodiments of the disclosure, the processor 330 may transmit the encrypted data or information indicating the selected key (for example, information indicating the size of the selected key in [Table 1] or the index indicating the selected key in [Table 2]) to the secure area.

[0061] According to various embodiments of the disclosure, the data corresponding to the user input stored in the normal area may be automatically deleted after encryption is completed. The encrypted data may be stored in the secure area. Since the data corresponding to the user input is not stored in the normal area of the memory 320 and access to the secure area needs separate authority, security of the electronic device 300 can be improved.

[0062] According to various embodiments of the disclosure, even though data transmitted / received within the electronic device 300 is exposed to an attacker, encrypted data is exposed due to encryption of the data corresponding to the user input, and thus security of the data can be improved.

[0063] According to various embodiments of the disclosure, since the size of the key to be used for encryption may be selected on the basis of the information quantity of the input data, it is possible to prevent encryption speed from being declined, which may be generated due to encryption of data having a small information quantity using a key having the excessively large size.

[0064] According to various embodiments of the disclosure, the processor 330 may identify, in the secure area, information indicating encrypted data which is the result of encryption performed in the normal area and the key used for encryption. The processor 330 may select one of a plurality of keys stored in the secure area on the basis of information indicating the key used for encryption. The processor 330 may decrypt the encrypted data in the secure area using the selected key.

[0065] According to various embodiments of the disclosure, the processor 330 may perform an operation corresponding to the user input on the basis of the decrypted data. For example, when the user input is a user input of inputting a password for switching the locked state of the electronic device 300 to the unlocked state, the processor 330 may identify whether the input password is the same as a preset password on the basis of the decrypted data and switch the electronic device 300 from the locked state to the unlocked state on the basis of the identification result. For example, when the user input is a user input of inputting a password for activating various services (for example, financial services) which the electronic device 300 can provide, the processor 330 may identify whether the input password is the same as a preset password on the basis of the decrypted data and determine whether to activate the various services which the electronic device 300 can provide on the basis of the identification result.

[0066] According to various embodiments of the disclosure, the password may be data implemented by a combination of characters / numbers, data implemented by pattern information in various forms which can be input into a display, data implemented by user's biometric information (for example, various pieces of biometric information including a user's fingerprint, iris, or face), or data in various type which can be implemented in the future.

[0067] According to various embodiments of the disclosure, the processor 330 may encrypt the input data through an encryption scheme (for example, an RSA encryption algorithm or an ECIES algorithm) using a public key and a private key.

[0068] According to various embodiments of the disclosure, the memory 320 may include a public key and a private key and store a plurality of key sets having different sizes of data. The plurality of key sets may have different sizes, and a public key and a private key included in one key set may have the same size. The processor 330 may identify an information quantity of the input data and select one of the plurality of key sets corresponding to the information quantity of the data. The processor 330 may encrypt the input data in the normal area by using the public key included in the selected key set. The processor 330 may move the encrypted data and information indicating the selected key set from the normal area to the secure area. The processor 330 may identify the key set used for encryption of the encrypted data on the basis of the information indicating the selected key set in the secure area. The processor 330 may decrypt the encrypted data using the private key included in the identified key set. The private key may be stored in the secure area of the memory 320, and the public key may be stored in the normal area of the memory 320.

[0069] According to various embodiments of the disclosure, the normal area and the secure area includes the public key and the private key and may have a plurality key sets having different sizes of data. The plurality of key sets may have different sizes, and a public key and a private key included in one key set may have the same size. The processor 330 may identify an information quantity of the input data and select one of the plurality of key sets stored in the normal area on the basis of the information quantity of the data. The processor 330 may encrypt the input data in the normal area by using the public key in the secure area included in the selected key set and the private key in the normal area. The processor 330 may move the encrypted data and information indicating the selected key set from the normal area to the secure area. The processor 330 may identify the key set used for encryption of the encrypted data on the basis of the information indicating the selected key set in the secure area. The processor 330 may decrypt the encrypted data using the public key in the normal area included in the identified key set and the private key in the secure area.

[0070] The above-described embodiments assume that the encryption keys have been generated in advance, but the electronic device 300 may newly generate an encryption key according to a data input according to various embodiments of the disclosure. The processor 330 may generate a predetermined encryption key having the length which is the same as the length of the input data. The predetermined encryption key may be one-time data used for encrypting the input data. The processor 330 may encrypt the input data (for example, perform the exclusive OR operation (XOR operation) using the predetermined encryption key and the input data) on the basis of the predetermined encryption key and transmit the encrypted data to the secure area. The processor 330 may decrypt the encrypted data (for example, perform the XOR operation again on the encrypted data on which the XOR operation has been performed) transmitted to the secure area.

[0071] FIG. 4 is a block diagram 400 illustrating the normal area and the secure area in the electronic device according to various embodiments of the disclosure.

[0072] Referring to FIG. 4, the electronic device 300 according to various embodiments of the disclosure may implement a normal area 410 and a secure area 420. The normal area 410 and the secure area 420 may be areas divided according to the operation of the processor (for example, the processor 330 of FIG. 3). The normal area 410 may be an area to which access is possible without any separate access authority. The secure area 420 may be an area which needs separate access authority for the secure area 420.

[0073] According to various embodiments of the disclosure, the normal area 410 may encrypt data corresponding to a user input and transmit the encrypted data to the secure area 420. The secure area 420 may receive the encrypted data and decrypt the encrypted data. The secure area 420 may perform an operation corresponding to the user input on the basis of the decrypted data.

[0074] According to various embodiments of the disclosure, the normal area 410 may include an input module 411, an information quantity identification module 413, a key selection module 415, and an encryption module 417.

[0075] According to various embodiments of the disclosure, the input module 411 may control a user interface (for example, the user interface 310 of FIG. 3) to display a screen for receiving a user input. The input module 411 may receive the user input through the user interface 310 and transmit data corresponding to the user input to the information quantity identification module 413.

[0076] According to various embodiments of the disclosure, the information quantity identification module 413 may receive the data transmitted by the input module 411 and identify the information quantity of the data. The information quantity of the data may be entropy of the data which is a value related to the number of cases of data having the same size as the input data.

[0077] According to various embodiments of the disclosure, the information quantity identification module 413 may identify types of elements (for example, letter, number, or special character) included in the input data and the number of elements included in the data, and identify the information quantity of the data on the basis of the types and the number of elements.

[0078] According to various embodiments of the disclosure, the key selection module 415 may select one of a plurality of keys on the basis of the information quantity of the data identified by the information quantity identification module. The selected key may be used for encryption of the data.

[0079] According to various embodiments of the disclosure, the plurality of keys may have different sizes and mapped with values related to the information quantity of the data. The key selection module 415 may identify the information quantity of the data and select a key corresponding to the information quantity of the data.

[0080] According to various embodiments of the disclosure, the encryption module 417 may encrypt the data received by the input module 411 using the key selected by the key selection module 415. The encryption module 417 may transmit the encrypted data and information indicating the key used for encryption of the data to the secure area 420. The information indicating the key used for encryption of the data may be information (key size data) indicating the size of the key and information (index) indicating the key.

[0081] According to various embodiments of the disclosure, the secure area 420 may include a decryption module 421 and a data processing module 423.

[0082] According to various embodiments of the disclosure, the decryption module 421 may receive the data encrypted by the encryption module 417 and the information indicating the key used for encryption of the data. The decryption module 421 may identify a key used for encryption on the basis of the information indicating the key. The decryption module 421 may decrypt the encrypted data using the identified key. The decryption module 421 may transmit the decrypted data to the data processing module 423.

[0083] According to various embodiments of the disclosure, the data processing module 423 may process the decrypted data transmitted by the decryption module 421. Processing the decrypted data may be performing an operation corresponding to the user input. For example, when the user input is a user input of inputting a password for switching the electronic device 300 from the locked state to the unlocked state, the data processing module 423 may identify whether a correct password is input on the basis of the decrypted data and switch the electronic device 300 from the locked state to the unlocked state on the basis of the identification result. For example, when the user input is a user input of inputting a password for activating various services (for example, financial services) which the electronic device 300 can provide, the data processing module 423 may identify whether a correct password is input on the basis of the decrypted data and determine whether to activate the various services which the electronic device 300 can provide on the basis of the identification result.

[0084] An electronic device according to various embodiments of the disclosure may include a user interface, a processor operatively connected to the user interface, and a memory operatively connected to the processor and including a normal area and a secure area, wherein the memory may be configured to store a plurality of keys for encrypting data corresponding to a user input and store instructions causing the processor, when executed, receive the data through the user interface, nontemporarily store the received data in the normal area, identify an information quantity of the stored data, select at least one of the plurality of keys stored in the memory, based on at least a portion of the identified information quantity, encrypt the data using the selected key, and transmit the encrypted data and information indicating the selected key to the secure area which demands access authority.

[0085] In the electronic device according to various embodiments of the disclosure, the instructions may cause the processor to identify a key used for encryption of the encrypted data, based on the information indicating the selected key and decrypt the encrypted data stored in the secure area by using the identified key.

[0086] In the electronic device according to various embodiments of the disclosure, the instructions may cause the processor to identify a certificate corresponding to the identified key, authenticate the identified key, based on the identified certificate, and determine whether to perform an encryption operation of the input data, based on a result of the authentication.

[0087] In the electronic device according to various embodiments of the disclosure, the plurality of keys stored in the memory may be configured to have different sizes of data, and a public key of the plurality of keys is stored in the normal area of the memory and a private key of the plurality of keys is stored in the secure area of the memory.

[0088] In the electronic device according to various embodiments of the disclosure, the memory may be configured to further store information indicating a key to be used according to a range of the information quantity of the data, and the instructions cause the processor to select a key mapped to the range corresponding to the information quantity of the input data.

[0089] In the electronic device according to various embodiments of the disclosure, information indicating a key to be used may include information mapped such that a size of the key used for encryption of the input data increases according to the size of the input data.

[0090] In the electronic device according to various embodiments of the disclosure, the instructions may cause the processor to generate a predetermined key having a length equal to a length of the data, and encrypt the input data by using the generated key.

[0091] In the electronic device according to various embodiments of the disclosure, the generated key may be configured to have an information quantity equal to or larger than the information quality of the data.

[0092] In the electronic device according to various embodiments of the disclosure, the memory may include a public key and a private key and may be configured to store a plurality of key sets having different sizes of data, and the instructions cause the processor to select one of the plurality of key sets, based on the information quantity of the input data, encrypt the input data by using the public key included in the selected key set, and transmit the encrypted data or information indicating the selected key set to the secure area.

[0093] In the electronic device according to various embodiments of the disclosure, the instructions may cause the processor to decrypt the encrypted data by using the private key included in the selected key set on the basis of the information indicating the selected key set.

[0094] FIG. 5 is a flowchart 500 illustrating a method of operating an electronic device according to various embodiments of the disclosure.

[0095] Referring to FIG. 5, in a method of operating an electronic device according to various embodiments of the disclosure, an electronic device (for example, the electronic device 300 of FIG. 3) may receive data corresponding to a user input.

[0096] According to various embodiments of the disclosure, the electronic device 300 may receive the user input corresponding to the data to be encrypted through a user interface (for example, the user interface 310 of FIG. 3).

[0097] According to various embodiments of the disclosure, the user input may be a user input of inputting a password for various functions which the electronic device 300 can provide. For example, the user input may be a user input of inputting a password for switching a locked state in which at least some functions are deactivated to an unlocked state in which at least some functions are activated. The password may be data implemented by a combination of characters / numbers, data implemented by pattern information in various forms which can be input into a display, data implemented by user's biometric information (for example, various pieces of biometric information including a user's fingerprint, iris, or face), or data in various type which can be implemented in the future.

[0098] According to various embodiments of the disclosure, the user interface 310 may be implemented in various forms for receiving a user input. For example, the user interface 310 may be implemented as a display. The display may display various screens on the basis of the control of the processor 330 and receive a user input on the display. The display may receive a user input corresponding to data to be encrypted. The display may display a screen for inputting a user input on the basis of the control of the processor 330, receive the user input in the state in which the screen is displayed, and transmit data corresponding to the user input to the processor 330. In another example, the user interface 310 may be a sensor module capable of acquiring user's biometric information. The user interface 310 may be implemented in the form of a fingerprint recognition sensor capable of acquiring user's fingerprint information in various types (for example, ultrasonic type or capacitive type), an infrared camera capable of acquiring user's iris information, and a Time of Flight (ToF) camera capable of acquiring user's face information.

[0099] According to various embodiments of the disclosure, in operation 520, the electronic device 300 may identify an information quantity of data.

[0100] According to various embodiments of the disclosure, the information quantity of the data may be entropy of the data corresponding to a value related to the number of cases of data having the same size as the input data. The electronic device 300 may identify types of elements (for example, letter, number, of special character) included in the input data and the number of elements included in the data, and identify the information quantity of the data on the basis of the types and the number of elements.

[0101] According to various embodiments of the disclosure, in operation 530, the electronic device 300 may select one of a plurality of keys on the basis of the information quantity of the data.

[0102] According to various embodiments of the disclosure, the plurality of keys may be stored in the memory 320. The plurality of keys may have different sizes, and the memory 320 may store data to which a range of the information quantity of data and information indicating the key are mapped to use different keys according to the information quantity of the data. The information indicating the key may be information (key size data) indicating the size of the key or information (index) indicating the key.

[0103] According to various embodiments of the disclosure, the electronic device 300 may select a key corresponding to the information quantity of the data.

[0104] According to various embodiments of the disclosure, in operation 540, the electronic device 300 may encrypt the data by using the selected key.

[0105] According to various embodiments of the disclosure, encryption of the input data may be performed in the normal area (for example, the normal area 410 of FIG. 4) on the basis of the control of the processor 330.

[0106] According to various embodiments of the disclosure, in operation 550, the electronic device 300 may transmit the encrypted data and information indicating the selected key to the secure area (for example, the secure area 420 of FIG. 4).

[0107] According to various embodiments of the disclosure, the data corresponding to the user input stored in the normal area may be automatically deleted after encryption is completed. The encrypted data may be stored in the secure area. The data corresponding to the user input may not be stored in the normal area of the memory 320, and access to the secure area demands separate authority, and thus security of the electronic device 300 can be improved.

[0108] According to various embodiments of the disclosure, due to encryption of the data corresponding to the user input, the encrypted data is exposed even though data transmitted / received within the electronic device 300 is exposed to an attacker, and thus security of the data can be improved.

[0109] FIG. 6 is a flowchart 600 illustrating the operation in a method of operating an electronic device according to various embodiments.

[0110] Referring to FIG. 6, in a method of operating an electronic device according to various embodiments of the disclosure, an electronic device (for example, the electronic device 300 of FIG. 3) may receive encrypted data and information indicating a selected key transmitted in a normal area (for example, the normal area 410 of FIG. 4) in operation 610.

[0111] According to various embodiments of the disclosure, the electronic device 300 may identify a key used for encryption on the basis of the information indicating the selected key in operation 620.

[0112] According to various embodiments of the disclosure, the information indicating the selected key may be information indicating the size of the key (key size data) or information (index) indicating the key.

[0113] According to various embodiments of the disclosure, the electronic device 300 may decrypt the encrypted data using the identified key in operation 630.

[0114] According to various embodiments of the disclosure, the electronic device 300 may perform an operation corresponding to a user input on the basis of the decrypted data. For example, when the user input is a user input of inputting a password for switching the electronic device 300 from the locked state to the unlocked state, the electronic device 300 may identify whether a correct password is input on the basis of the decrypted data and switch the electronic device 300 to the locked state to the unlocked state on the basis of the identification result. For example, when the user input is a user input of inputting a password for activating various services (for example, financial services) which the electronic device 300 can provide, the electronic device 300 may identify whether a correct password is input on the basis of the decrypted data and determine whether to activate the various services which the electronic device 300 can provide on the basis of the identification result.

[0115] A method of operating an electronic device according to various embodiments of the disclosure may include an operation of receiving data corresponding to a user input through a user interface, an operation of nontemporarily storing the received data in a normal area of a memory, an operation of identifying an information quantity of the stored data, an operation of selecting one of a plurality of keys stored in the memory on the basis of at least a portion of the information quantity of the data, an operation of encrypting the data by using the selected key, and an operation of transmitting the encrypted data and information indicating the selected key to a secure area which demands access authority.

[0116] The method of operating the electronic device according to various embodiments of the disclosure may further include an operation of identifying a key used for encryption of the encrypted data, based on the information indicating the selected key and an operation of decrypting the encrypted data stored in the secure area by using the identified key.

[0117] The method of operating the electronic device according to various embodiments of the disclosure may further include an operation of identifying a certificate corresponding to the identified key, an operation of authenticating the identified key, based on the identified certificate, and an operation of determining whether to decrypt the encrypted data, based on a result of the authentication.

[0118] In the method of operating the electronic device according to various embodiments of the disclosure, the plurality of keys stored in the memory may be configured to have different sizes of data, and a public key of the plurality of keys may be stored in the normal area of the memory and a private key of the plurality of keys may be stored in the secure area of the memory.

[0119] The method of operating the electronic device according to various embodiments of the disclosure may further include an operation of identifying information indicating a key to be used for encryption according to a range of the information quantity of the data and an operation of selecting a key mapped to the range corresponding to the information quantity of the input data.

[0120] In the method of operating the electronic device according to various embodiments of the disclosure, information indicating a key to be used may include information mapped such that a size of the key used for encryption of the input data increases according to the size of the input data.

[0121] The method of operating the electronic device according to various embodiments of the disclosure may further include an operation of generating a predetermined key having a length equal to a length of the data and an operation of encrypting the input data by using the generated key.

[0122] In the method of operating the electronic device according to various embodiments of the disclosure, the generated key may be configured to have an information quantity equal to or larger than the information quality of the data.

[0123] The method of operating the electronic device according to various embodiments of the disclosure may further include an operation of selecting one of the plurality of key sets including a public key and a private key on the basis of the information quantity of the input data, an operation of encrypting the input data by using the public key included in the selected key set, and an operation of transmitting the encrypted data or information indicating the selected key set to the secure area.

[0124] The method of operating the electronic device according to various embodiments of the disclosure may further include an operation of decrypting the encrypted data by using the private key included in the selected key set on the basis of the information indicating the selected key set.

[0125] The electronic device according to various embodiments may be one of various types of electronic devices. The electronic devices may include, for example, a portable communication device (e.g., a smartphone), a computer device, a portable multimedia device, a portable medical device, a camera, a wearable device, or a home appliance. According to an embodiment of the disclosure, the electronic devices are not limited to those described above.

[0126] It should be appreciated that various embodiments of the disclosure and the terms used therein are not intended to limit the technological features set forth herein to particular embodiments and include various changes, equivalents, or replacements for a corresponding embodiment. With regard to the description of the drawings, similar reference numerals may be used to refer to similar or related elements. It is to be understood that a singular form of a noun corresponding to an item may include one or more of the things, unless the relevant context clearly indicates otherwise. As used herein, each of such phrases as "A or B," "at least one of A and B," "at least one of A or B," "A, B, or C," "at least one of A, B, and C," and "at least one of A, B, or C," may include any one of, or all possible combinations of the items enumerated together in a corresponding one of the phrases. As used herein, such terms as "1st" and "2nd," or "first" and "second" may be used to simply distinguish a corresponding component from another, and does not limit the components in other aspect (e.g., importance or order). It is to be understood that if an element (e.g., a first element) is referred to, with or without the term "operatively" or "communicatively", as "coupled with," "coupled to," "connected with," or "connected to" another element (e.g., a second element), it means that the element may be coupled with the other element directly (e.g., wiredly), wirelessly, or via a third element.

[0127] As used herein, the term "module" may include a unit implemented in hardware, software, or firmware, and may interchangeably be used with other terms, for example, "logic," "logic block," "part," or "circuitry". A module may be a single integral component, or a minimum unit or part thereof, adapted to perform one or more functions. For example, according to an embodiment, the module may be implemented in a form of an application-specific integrated circuit (ASIC).

[0128] Various embodiments as set forth herein may be implemented as software (e.g., the program 140) including one or more instructions that are stored in a storage medium (e.g., internal memory 136 or external memory 138) that is readable by a machine (e.g., the electronic device 101) . For example, a processor(e.g., the processor 120) of the machine (e.g., the electronic device 101) may invoke at least one of the one or more instructions stored in the storage medium, and execute it, with or without using one or more other components under the control of the processor. This allows the machine to be operated to perform at least one function according to the at least one instruction invoked. The one or more instructions may include a code generated by a complier or a code executable by an interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Wherein, the term "non-transitory" simply means that the storage medium is a tangible device, and does not include a signal (e.g., an electromagnetic wave), but this term does not differentiate between where data is semi-permanently stored in the storage medium and where the data is temporarily stored in the storage medium.

[0129] According to an embodiment, a method according to various embodiments of the disclosure may be included and provided in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read only memory (CD-ROM)), or be distributed (e.g., downloaded or uploaded) online via an application store (e.g., PlayStoreTM), or between two user devices (e.g., smart phones) directly. If distributed online, at least part of the computer program product may be temporarily generated or at least temporarily stored in the machine-readable storage medium, such as memory of the manufacturer's server, a server of the application store, or a relay server.

[0130] According to various embodiments, each component (e.g., a module or a program) of the above-described components may include a single entity or multiple entities. According to various embodiments, one or more of the above-described components may be omitted, or one or more other components may be added. Alternatively or additionally, a plurality of components (e.g., modules or programs) may be integrated into a single component. In such a case, according to various embodiments, the integrated component may still perform one or more functions of each of the plurality of components in the same or similar manner as they are performed by a corresponding one of the plurality of components before the integration. According to various embodiments, operations performed by the module, the program, or another component may be carried out sequentially, in parallel, repeatedly, or heuristically, or one or more of the operations may be executed in a different order or omitted, or one or more other operations may be added.

Claims

1. An electronic device (300) comprising: a user interface (310); a processor (330) operatively connected to the user interface; and a memory (320) operatively connected to the processor and comprising a normal area and a secure area, wherein the memory is configured to store a plurality of keys for encrypting user input data corresponding to a user input and store instructions causing the processor, when executed, receive the data through the user interface, nontemporarily store the received data in the normal area, identify an information quantity of the stored data, select at least one of the plurality of keys stored in the memory, based on at least a portion of the identified information quantity, encrypt the stored data using the selected key, and transmit the encrypted data and information indicating the selected key to the secure area which demands access authority, wherein the memory is configured to further store information indicating a key to be used according to a range of the information quantity of the user input data, and wherein the instructions cause the processor to select the key mapped to the range corresponding to the information quantity of the user input data such that the electronic device encrypts the stored data by using the key having smaller size as the information quantity of the input data decreases.

2. The electronic device of claim 1, wherein the instructions cause the processor to identify a key used for encryption of the encrypted data, based on the information indicating the selected key and decrypt the encrypted data stored in the secure area by using the identified key.

3. The electronic device of claim 2, wherein the instructions cause the processor to identify a certificate corresponding to the identified key, authenticate the identified key, based on the identified certificate, and determine whether to perform an encryption operation of the input data, based on a result of the authentication.

4. The electronic device of claim 1, wherein the plurality of keys stored in the memory are configured to have different sizes of data, and a public key of the plurality of keys is stored in the normal area of the memory and a private key of the plurality of keys is stored in the secure area of the memory.

5. The electronic device of claim 1, wherein information indicating a key to be used includes information mapped such that a size of the key used for encryption of the input data increases according to the size of the input data.

6. The electronic device of claim 1, wherein the instructions cause the processor to generate a predetermined key having a length equal to a length of the data, and encrypt the input data by using the generated key.

7. The electronic device of claim 6, wherein the generated key is configured to have an information quantity equal to or larger than the information quality of the data.

8. The electronic device of claim 1, wherein the memory comprises a public key and a private key and is configured to store a plurality of key sets having different sizes of data, and the instructions cause the processor to select one of the plurality of key sets, based on the information quantity of the input data, encrypt the input data by using the public key included in the selected key set, and transmit the encrypted data or information indicating the selected key set to the secure area.

9. The electronic device of claim 8, wherein the instructions cause the processor to decrypt the encrypted data by using the private key included in the selected key set, based on the information indicating the selected key set.

10. A method of operating an electronic device, the method comprising: receiving user input data corresponding to a user input through a user interface (510); nontemporarily storing the received data in a normal area of a memory; identifying an information quantity of the stored data (520); selecting one of a plurality of keys stored in the memory, based on at least a portion of the information quantity of the stored data (530); encrypting the stored data by using the selected key (540); and transmitting the encrypted data and information indicating the selected key to a secure area which demands access authority (550); wherein the method further comprises: identifying information indicating a key to be used for encryption according to a range of the information quantity of the user input data; and selecting the key mapped to the range corresponding to the information quantity of the user input data such that the electronic device encrypts the stored data by using the key having smaller size as the information quantity of the input data decreases.

11. The method of claim 10, further comprising: identifying a key used for encryption of the encrypted data, based on the information indicating the selected key; and decrypting the encrypted data stored in the secure area by using the identified key.

12. The method of claim 11, further comprising: identifying a certificate corresponding to the identified key; authenticating the identified key, based on the identified certificate; and determining whether to perform an encryption operation of the input data, based on a result of the authentication.

13. The method of claim 10, wherein the plurality of keys stored in the memory are configured to have different sizes of data, and a public key of the plurality of keys is stored in the normal area of the memory and a private key of the plurality of keys is stored in the secure area of the memory.