Crypto Lab Inc.

Yongsoo Song

Jung Hee Cheon

Kyoohyung Han

Duhyeong Kim

Junghee Cheon

Miran Kim

Chanhwa Lee

Hyungbo Shim

Junsoo Kim

Andrey Kim

An operation apparatus and method for processing a homomorphic encrypted message are disclosed. The method includes producing an approximate polynomial corresponding to an operation function to be applied to a homomorphic encrypted message and approximately operating the homomorphic encrypted message using the approximate polynomial. Thus, an encrypted message may be efficiently processed.

Apparatus for approximately processing encrypted messages and methods thereof

A decryption method includes: receiving a homomorphic ciphertext; and obtaining a result value added an error value at a message from the received homomorphic ciphertext. The error is disposed on the least significant bit (LSB) side in the homogeneous ciphertext, and the message is disposed at a position adjacent to the error.

Terminal device performing homomorphic encryption, server device processing ciphertext and methods thereof

An encryption method of a terminal device includes: setting a scaling factor; and reflecting the scaling factor in a message to be encrypted, and performing encryption using a public key to generate a homomorphic ciphertext. The homomorphic encryption is, based on a decryption being performed, in a form that a result value obtained by adding an error value to a value obtained by reflecting the scaling factor in the message is restored.

The computer-implemented method for authenticating secret information according to an aspect of the present disclosure, comprises receiving, by an authentication server, Q{right arrow over (X)} from a terminal for registering secret information; storing, by the authentication server, the received Q{right arrow over (X)}; receiving, by the authentication server, a vector {right arrow over (Z)} from a terminal for requesting authentication of secret information; calculating, by the authentication server, the inner product of Q{right arrow over (X)} and {right arrow over (Z)}; calculating, by the authentication server, &#xbd;(n&#x2212;the inner product); and determining, by the authentication server, that the authentication is successful if &#xbd;(n&#x2212;the inner product) is within a predetermined value and that the authentication fails otherwise.

Method for authenticating secret information which protects secret information

The present disclosure provides a computer-implemented method for processing dynamic data by dynamic data processing device. The device comprises a homomorphic encryption module and a plurality of computing modules running in parallel. The method comprises carrying out, by the homomorphic encryption module, fully homomorphic encryption to dynamic data received from an object which generates the dynamic data; updating, by the computing module which is not in bootstrapping, the encrypted state variable; and carrying out, by the computing module which completes bootstrapping, the first update to the encrypted state variable. The first update to the encrypted state variable after completion of bootstrapping is carried out by(t+N)&#x2192;A(t)+&#x3a3;AB((t+j)&#x2212;(t+j)).

Method for processing dynamic data by fully homomorphic encryption method

An encryption method is provided. According to the encryption method, a scaling factor may be reflected in a message and then, a homomorphic ciphertext may be generated using a public key. The generated ciphertext is, when decryption is performed, generated in a form that a result value obtained by adding an error value to a value obtained by reflecting the scaling factor in the message is restored. Accordingly, a homomorphic ciphertext capable of being computed in a ciphertext state can be effectively generated.

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Seoul, South Korea

Yongsoo Song