Samsung Sds Co., Ltd.

Kookmin University

Ji Hoon Kwon

Hyo Jin Yoon

Eun Kyung Kim

Tae Ho Lee

Young Hyun Kim

Joo Hee Lee

Jung Hoon Sohn

Ji Hoon Cho

Duk Jae Moon

Jin Hyuck Jeong

Dong Guk Han

Sang Yub Lee

Jang Hyuk Ahn

Jae Won Huh

Bo Yeon Sim

Jong Hyeok Lee

Jae Seung Han

Il Ju Kim

Keon Hee Choi

A method for preventing side-channel attack according to an embodiment includes generating an order table which includes a position index value for each bit value of a bit string that is secret information to be generated through a decryption algorithm of an NDegree Truncated Polynomial Ring Units (NTRU) LPRime algorithm, shuffling a sort order of the position index value for the each bit value in the order table based on a random number, determining a generation order for the each bit value according to the sort order of the position index value for the each bit value in the order table, and generating the secret information through the decryption algorithm. The secret information is generated by generating the each bit value according to the determined generation order.

Apparatus and method for preventing side channel attack for NTRU LPRime algorithm

A method for performing an operation according to one embodiment includes performing a homomorphic operation using one or more ciphertexts that are homomorphically encrypted based on an encryption key, determining a count value for a ciphertext generated through the homomorphic operation based on count values for each of the one or more ciphertexts, requesting a key management apparatus, which holds the encryption key and a decryption key corresponding to the encryption key, to re-encrypt the generated ciphertext based on the determined count value, acquiring, from the key management apparatus, a ciphertext generated by re-encrypting the generated ciphertext through decryption based on the decryption key and encryption based on the encryption key; and determining a count value for the acquired ciphertext to be a preset initial value.

Method and apparatus for performing operation using encrypted data

Growing community of inventors

Seoul, South Korea

Ji Hoon Kwon