The present invention concerns a method for secure data classification by a computer platform. A client sends to the platform data to be classified in encrypted form using a first symmetric key. Similarly, a supplier sends to the platform parameters of a classification model in encrypted form using a second symmetric key. The invention uses a homomorphic cryptosystem defined by a public key and a private key. The platform performs a first transcryption step by deciphering the data to be classified in the homomorphic domain and a second transcryption step by deciphering the model parameters in the homomorphic domain. The classification function is then evaluated in the homomorphic domain for providing a classification result encrypted by said public key.

A method and apparatus for obtaining a privacy set intersection are provided. The method may include: encrypting a privacy set of an intersection initiator by using a homomorphic encryption algorithm to generate a cipher text, a cipher text function, a public key, and a private key of the intersection initiator; delivering the cipher text, the cipher text function, and the public key of the intersection initiator to an intersection server; receiving a to-be-decrypted function value of a privacy set of the intersection server from the intersection server; and decrypting the to-be-decrypted function value of the privacy set of the intersection initiator by using the private key, to obtain an intersection element of the privacy set of the intersection initiator and the privacy set of the intersection server.

Various embodiments relate to a method for masked decoding of a polynomial a using an arithmetic sharing a to perform a cryptographic operation in a data processing system using a modulus q, the method for use in a processor of the data processing system, including: subtracting an offset δ from each coefficient of the polynomial a; applying an arithmetic to Boolean (A2B) function on the arithmetic shares of each coefficient a.sub.i of the polynomial a to produce Boolean shares â.sub.i that encode the same secret value a.sub.i; and performing in parallel for all coefficients a shared binary search to determine which of coefficients a.sub.i are greater than a threshold t to produce a Boolean sharing value {circumflex over (b)} of the bitstring b where each bit of b decodes a coefficient of the polynomial a.

A method for performing a matrix multiplication operation being secure against side-channel attacks according to one embodiment, which is performed by a computing device comprising one or more processors and a memory storing one or more programs to be executed by the one or more processors, includes shuffling an order of execution of multiplication operations between elements of a first matrix and elements of a second matrix for a matrix multiplication operation between the first matrix and the second matrix; and performing the matrix multiplication operation based on the shuffled order of execution.

Low-resource overhead computer-implemented methods for enrolling, authenticating and establishing encryption keys for one or more queried devices, each of the queried devices including an electrical circuit configured to output electrical signals indica-five of a physically unclonable function (PUF) of the queried device. Authentication and encryption are implemented in low-resource queried device computational architectures, with embodiments of the present invention utilizing pseudo-random number generators configured based on unique primitive polynomials, masking and unmasking functions, and error correction protocols executed in a querying device.

A method is suggested for providing a response, wherein the method comprises: obtaining a challenge from a host, determining the response based on the challenge, determining an auxiliary value based on the response or the challenge, providing the auxiliary value to the host, obtaining a random value from the host, checking the validity of the challenge based on the random value, and providing the response to the host only if the challenge is valid. Also, corresponding methods running on the host and system are provided. Further, corresponding devices, hosts and systems are suggested.

A homomorphic encryption processing device includes the processing circuitry is configured to generate ciphertext operation level information based on field information. The field information represents a technology field to which homomorphic encryption processing is applied. The ciphertext operation level information represents a maximum number of multiplication operations between homomorphic ciphertexts without a bootstrapping process. The processing circuitry is further configured to select and output a homomorphic encryption parameter based on the ciphertext operation level information. The processing circuitry is further configured to perform one of a homomorphic encryption, a homomorphic decryption and a homomorphic operation, based on the homomorphic encryption parameter. The homomorphic encryption processing device may adaptively generate a homomorphic encryption parameter according to a ciphertext operation level information determined based on a field information, and may perform a homomorphic encryption, a homomorphic decryption and a homomorphic operation based on the homomorphic encryption parameter.

Polynomial function secret sharing provides for computation of reconstruction share results for a polynomial function on an input. An allocatable share of the polynomial function is received at a computing system of the share result computation systems. The allocatable share is generated from the polynomial function. Each of the allocatable shares is distributed to a unique share result computation system of the share result computation systems. Each allocatable share includes a share element for each coefficient in the polynomial function, wherein the share elements for a coefficient across the share result computation systems summing to the coefficient. A reconstruction share result is generated at the computing system by computing a dot product of the input and the allocatable share received by the computing system. A combination of the reconstruction share results generated by the share result computation systems yields a reconstructed result of the polynomial function on the input.

According to an embodiment of the present disclosure, a ring-learning with rounding (LWR)-based quantum-resistant signature method includes: a key generation step of receiving a security parameter, and outputting a signature key and a verification key, via an operation on a ring defined by a cyclotomic equation including three terms; a signature value output step of outputting a signature value based on the output signature key; and a signature verification step of calculating an operation value based on the output verification key and signature value, and verifying a signature based on a result of comparing the output signature value with the calculated operation value.

Provided is a non-transitory computer readable medium. The non-transitory computer readable medium storing program code that, when is executed by a processor, causes the processor to calculate a message, based on a first cipher text, a second cipher text, and a private key, to compare a coefficient of the message with a reference value based on a prime number, to decide a coefficient of a modified message, based on a comparison result between the coefficient of the message and the reference value, and to decrypt the modified message.