The present invention discloses an online and offline circulating unbalanced oil and vinegar signature method, which decomposes the traditional unbalanced oil and vinegar signature process into offline and online parts, wherein the offline step is independent of the signature message, and can be performed in advance, and a combination of circulating calculation methods is used in the calculating process to improve performance. When the online part needs to be signed, the final signature operation is completed by using the calculated result stored in the offline step. The present invention is a multi-variable public key cryptosystem-based unbalanced oil and vinegar signature scheme, which is a lightweight digital signature scheme suitable for low-performance electronic devices. The invention decomposes the unbalanced oil and vinegar signature algorithm into offline and online parts, and the offline step calculation can be performed in advance, which can more fully utilize energy and accelerate the online signature process simultaneously. In the calculation of the offline step, the present invention uses a circulating calculation method, which greatly reduces the size of the secret key and shortens the signature period.

A logic circuit for quantum-resistant cryptoprocessing. The logic circuit includes a first plurality of multiplexers, a second plurality of multiplexers, a plurality of AND gates, a third plurality of multiplexers, a plurality of shift registers, a plurality of inverters, a fourth plurality of multiplexers, a plurality of adders, a plurality of XOR gates, a fifth plurality of multiplexers, and a plurality of parallel outputs.

Provided is a system and method for confidential string-matching and confidential deep-packet inspection. The method includes: receiving encrypted ciphertexts from a first computing device; windowing a text corpus and applying a hash; performing binning and splitting on the corpus set of hashes; performing batching on the binned and split corpus set of hashes; determining match ciphertexts by evaluating a homomorphic encryption circuit between the encrypted ciphertexts and the batched corpus set of hashes; and communicating the match ciphertexts to the first computing device, the confidential string matching determinable by the first computing device by: decrypting the match ciphertexts, determining from the decryption output, if the hash value for each pattern window matches the hash value for any corpus windows and if the matched windows are adjacent in the corpus.

An apparatus comprises an input register comprising an input polynomial, a processing datapath communicatively coupled to the input register comprising a plurality of compute nodes to perform a number theoretic transform (NTT) algorithm on the input polynomial to generate an output polynomial in NTT format. The plurality of compute nodes comprises at least a first butterfly circuit to perform a series of butterfly calculations on input data and a randomizing circuitry to randomize an order of the series of butterfly calculations.

Bitcoins and the underlying blockchain technology are one of the main innovations in building decentralized applications. The effects of quantum computing on this technology are analyzed in general. Provided herein are effective solutions to address security vulnerabilities in a blockchain-based system that can be exploited by a quantum attacker.

A computer-implemented method and a distributed computer system (100) for privacy-preserving distributed training of a global neural network model on distributed datasets (DS1 to DSn). The system has a plurality of data providers (DP1 to DPn) being communicatively coupled. Each data provider has a respective local training dataset (DS1 to DSn) and a vector of output labels (OL1 to OLn) for training the global model. Further, it has a portion of a cryptographic distributed secret key (SK1 to SKn) and a corresponding collective cryptographic public key (CPK) of a multiparty fully homomorphic encryption scheme, with the weights of the global model being encrypted with the collective public key. Each data provider (DP1) computes and aggregates, for each layer of the global model, encrypted local gradients (LG1) using the respective local training dataset (DS1) and output labels (OL1), with forward pass and backpropagation using stochastic gradient descent. At least one data provider homomorphically combines at least a subset of the current local gradients of at least a subset of the data providers into combined local gradients, and updates the weights of the current global model (GM) based on the combined local gradients.

A system and method for encryption of data. The system and method utilizes a cryptographic function that provides asymmetric encryption/decryption and digital signing capabilities that are hardened against cyber attack from quantum computers.

An encoder for encrypting a plaintext into a ciphertext. The encoder has an encoding submodule for acting as a deterministic random bit generator (DRBG) in an offline mode for generating one or more hash-key value candidates, and for acting as a stream encryptor in an online mode for encrypting the plaintext into the ciphertext; a hash key selector for selecting a hash-key value H from the one or more hash-key value candidates; and a hash submodule for generating a MAC tag using at least the ciphertext and the selected hash-key value H. A corresponding decoder is also provided.

Polynomial multiplication for side-channel protection in cryptography is described. An example of an apparatus includes one or more processors to process data; a memory to store data; and polynomial multiplier circuitry to multiply a first polynomial by a second polynomial, the first polynomial and the second polynomial each including a plurality of coefficients, the polynomial multiplier circuitry including a set of multiplier circuitry, wherein the polynomial multiplier circuitry is to select a first coefficient of the first polynomial for processing, and multiply the first coefficient of the first polynomial by all of the plurality of coefficients of the second polynomial in parallel using the set of multiplier circuits.

According to an example aspect of the present invention, there is provided an apparatus comprising at least one processing core, at least one memory including computer program code, the at least one memory and the computer program code configured to cause the apparatus to receive an identifier of a function, encrypted input data, an encrypted computation result, encrypted random data and an encrypted output of the function, when nm with the random data, obtain a homomorphic polynomial factorization of the function, comprising obtaining a decomposed representation of the function, the representation comprising a sum of polynomials, and verify that the computation result is correct by checking, whether a difference between the encrypted output and the encrypted computation result equals a value of the decomposed representation, wherein the encrypted random data and the encrypted input data are used as parameter values in the sum of polynomials.