Crypto Lab Inc.

Seoul National University

Samsung Sds Co., Ltd.

Samsung Electronics Co., Ltd.

Snu Rdb Foundation

Crypto Lab Inc., Et Al.

Jung Hee Cheon

Hyo Jin Yoon

Duhyeong Kim

Yongsoo Song

Kyoohyung Han

Jinhyuck Jeong

Jai Hyun Park

Hyeongmin Choe

Dongwoo Kim

Eunah Kim

Jinsu Kim

Junbum Shin

Joo Hee Lee

Seon Young Lee

Jeong Hyun Yi

Hyung Lee

Jung Hoon Sohn

Eunkyung Kim

Andrey Kim

Dongyeon Hong

Yongha Son

Donggeon Yhee

Taekyung Kim

Wonhee Cho

Taekyoung Kwon

Jin Il Hong

Sumin Kim

Du Hyeong Kim

Yong Ho Hwang

Mun-Kyu Lee

Miran Kim

Tae Kyoung Kwon

Jae Woo Seo

Wootae Kim

Kyoo Hyung Han

Jae Seon Kim

Unyoung Kim

Seungwan Hong

Keewoo Lee

Do Hyeong Ki

Heewon Chung

Yongdong Yeo

Minki Hhan

Jeongdae Hong

Soo Yeon Shin

The electronic device includes: a communicator communicating with a plurality of external devices each generating an encryption key; a memory; and a processor, wherein the processor stores a plurality of encrypted messages in the memory when receiving the plurality of encrypted messages each encrypted with the encryption key by the plurality of external devices through the communicator, performs a key switching operation using a switching key for the plurality of encrypted messages to change each of the plurality of encrypted messages to the encrypted message encrypted with a common key, and evaluates the changed plurality of encrypted messages by using at least one evaluation key.

Electronic device for performing evaluation of encrypted messages and methods thereof

Disclosed is an electronic device. The electronic device includes a communicator, a memory configured to store data for generating a key, and a processor. The processor may generate a secret key by randomly combining values within a preset range based on the data stored in the memory, generate a public key using the secret key and an error, and store the secret key and the public key in the memory, transmit the public key to an external device using the communicator, and a sum of the number of remaining values other than zero (0), among the values within the preset range, may correspond to a Hamming weight. Accordingly, encryption and decryption may be performed efficiently.

Electronic device for encrypting data by public key and methods thereof

Provided are an electronic apparatus and a method for verifying encrypted data. The verification method of the electronic apparatus includes transmitting encrypted quotient polynomial rings to an external device, receiving, from the external device, a result value calculated through an operation process for at least one layer on the basis of the transmitted encrypted polynomial rings, transmitting a random value to the external device, and receiving claim data obtained by performing the operation process in a reverse order on the basis of the random value from the external device, and verifying the received result value on the basis of a value of the quotient polynomial rings corresponding to the random value and the received claim data.

Electronic apparatus and method for verifying encrypted data

Disclosed is an electronic device including: a memory storing a lookup table including identification information and data matched to the identification information; an interface; and a processor configured to search the data matched to the identification information corresponding to search information by generating a position identification vector including the number of elements corresponding to the number of the lookup table, and repeatedly performing an operation of updating the position identification vector based on a comparison calculation result based on the search information and each segmented table part while segmenting the lookup table into a plurality of parts, in case of receiving the search information through the interface. Accordingly, the device may perform effective data search on the table including a homomorphically encrypted message.

Electronic device for searching encrypted data and methods thereof

An electronic apparatus includes a communication apparatus communicating with an external apparatus, a memory storing a message, and a processor generating a digital signature for the message, wherein the processor generates a first signature ciphertext and a message ciphertext by encrypting each of first signature information and the message by using a homomorphic encryption public key, obtains encrypted third signature information generated using second signature information, an element value corresponding to the second signature information, the first signature ciphertext, and the message ciphertext, and calculates a first digital signature value included in the digital signature by using the first signature information and the second signature information, calculate a second digital signature value included in the digital signature by decrypting the encrypted third signature information, and generate the digital signature by using the calculated first digital signature value and second digital signature value.

Apparatus for generating blind signature and method thereof

An electronic apparatus is disclosed. The electronic apparatus includes a memory configured to store a homomorphic ciphertext including a tag and a program operating in the electronic apparatus, a user interface, and a processor, and the tag includes type information for original data of the homomorphic ciphertext, and is set, based on computation for the homomorphic ciphertext being performed, such that the tag included in the homomorphic ciphertext used in the computation is included in even a computation result value generated by the computation being performed, and the processor is configured to generate, based on receiving a computation request for the homomorphic ciphertext from the program, a computation result value by performing computation for the homomorphic ciphertext, check the type information for the original data of the homomorphic ciphertext used in the computation based on the tag included in the computation result value, perform decryption of the computation result value, control the user interface to display the checked type information for the original data and the decrypted computation result value, and provide, based on receiving a command to provide data through the user interface, the decrypted computation result value to the program.

Electronic apparatus using homomorphic cipher and method thereof

A calculation device is disclosed. The calculation device includes: a memory storing at least one instruction and identity information; and a processor performing the at least one instruction, wherein the processor may randomly sample small elements, generate a function-processed output value by function-processing the stored identity information, and generate an encrypted text for a message by using a master public key computed using a ring having a dimension (d) represented by a power of 2 and an integer multiplication of 3 or more, the sampled small elements and the function-processed output value.

Identity-based encryption method based on lattices

Disclosed is a calculation device. The present calculation device includes: a memory for storing a plurality of homomorphic ciphertexts for an approximate message including an error; and a processor for sorting the plurality of homomorphic ciphertexts by using a 5-way sorter which can sort five homomorphic ciphertexts in a single stage.

Practical sorting on large-scale encrypted data

An encoding method includes: receiving a plurality of messages; encoding the plurality of messages into a polynomial defined by multivariates; and encrypting the polynomial defined by the multivariates to generate a homomorphic ciphertext. The plurality of messages may be multidimensionally packed by using multivariates, and thus, an operation may be performed with low complexity in the process of matrix multiplication for ciphertexts packed with the multivariates.

Operating device and method using multivariate packing

An electronic device is disclosed. The device may comprise: a storage unit in which tag information is stored; a communication unit; and a processor which: acquires a biometric code string from biometric data sensed by a sensor; transmits a first cryptogram obtained by encrypting the biometric code string and the tag information, a first masking code, and a first masking encryption code obtained by encrypting the first masking code to the server through the communication unit; when tag information contained in a second cryptogram received from the server is identified as a value acquired on the basis of the stored tag information, decrypts the second cryptogram so as to acquire a value obtained by adding a distance value and a second masking code derived from the second cryptogram; and transmits the acquired value to the server through the communication unit, wherein the distance value includes a distance value between the biometric code string and a biometric code string already stored in the server, and the second masking code includes a code acquired by the server on the basis of the first masking code.

Electronic device for user authentication, server, and control method therefor

A mobile device is disclosed. The device includes a communicator, a GPS unit for calculating location information, a memory, a display, and a processor, and the processor is configured to generate movement path information of the mobile device by performing homomorphic encryption of a plurality of pieces of location information stored in the memory, transmit the movement path information to a server apparatus through the communicator, based on operation result data obtained by operating based on the movement path information and comparison target path information being transmitted from the server apparatus, decrypt the operation result data, and output a message notifying whether a route overlaps the comparison target path information based on a decrypted result through the display. Therefore, the route overlap is rapidly and accurately confirmed without invasion of privacy.

Mobile device for detecting route overlap and methods thereof

In a method of generating a secret key according to an embodiment, a share of each of a user and a plurality of other users for a secret key of the user are generated, the share of each of the plurality of other users is provided to a user terminal of each of the plurality of other users, a share of the user for a secret key of each of the plurality of other users is received from the user terminal of each of the plurality of other users, and a new secret key of the user is generated using the share of the user for the secret key of the user and the shares of the user for the secret key of each of the plurality of other users.

Apparatus and method for generating secret key, apparatus and method for generating evaluation key

Disclosed is a ciphertext calculation method. The ciphertext calculation method comprises the steps of: receiving a comparative calculation command for a plurality of ciphertexts of the same type; performing a calculation by reflecting the plurality of ciphertexts of the same type on a synthesis function corresponding to the comparative calculation command; and outputting the calculated ciphertexts of the same type.

Apparatus and method for processing non-polynomial operation on encrypted messages

A method of operating a homomorphic ciphertext is disclosed. The method of operating a homomorphic ciphertext includes receiving a non-polynomial operation command with respect to a homomorphic ciphertext, computing an approximate polynomial function corresponding to the non-polynomial operation, performing an operation of the homomorphic ciphertext using the computed polynomial function, and outputting the operated homomorphic ciphertext, wherein the approximate polynomial function is a second approximate polynomial function which is obtained by extending a first approximate polynomial function to have a second range wider than the first range having a preset accuracy with the non-polynomial operation within a first range.

Apparatus for processing non-polynomial operation on homomorphic encrypted messages and methods thereof

A method of generating a secret key according to one embodiment includes generating a share of each of a user and a plurality of other users for a secret key of the user, providing the share of each of the plurality of other users to a user terminal of each of the plurality of other users, receiving a share of the user for a secret key of each of the plurality of other users from the user terminal of each of the plurality of other users, and generating a new secret key of the user using the share of the user for the secret key of the user and the shares of the user for the secret key of each of the plurality of other users.

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Seoul, South Korea

Jung Hee Cheon