According to an embodiment, a number-theoretic transform processing apparatus for a noise in lattice-based cryptography, includes a processor configured to perform number-theoretic transform of the noise using a precomputation table including a combination of products of one or more elements that belong to a subspace of a finite field Zq and indicate coefficients of the noise, with one or more number-theoretic transform constants.

In a method for determining the modular inverse of a number, successive iterations are applied to two pairs each including a first variable and a second variable, such that at the end of each iteration and for each pair, the product of the second variable and of the number is equal to the first variable modulo a given module. Each iteration includes at least one division by two of the first variable of a first pair or of a second pair, or a combination of the first variable of the first pair and of the first variable of the second pair by addition or subtraction. At least some of the iterations including a combination by addition or subtraction include a step of storing the result of the combination in the first variable of a pair determined randomly from among the first pair and the second pair. An associated cryptographic processing device is also described.

A computer processing system and method for reducing memory footprint that includes initiating, through at least one computer processor, a cryptography session utilizing an i-degree isogeny arithmetic computation having chained computations therein. The cryptography session includes implementing a first iteration cycle, of a plurality of iteration cycles, and a implementing a remaining amount of the plurality of iteration cycles, each of the plurality iteration cycles computing isogenies using a compressed Z value to complete the -degree isogeny arithmetic computation. The first iteration cycle includes individually computing a plurality of sequentially occurring pivot points within the chained computations, implementing a Co—Z algorithm within the plurality of sequentially occurring pivot points to compute and store the compressed Z value on one of the plurality of temporary registers and computing a first isogeny of the -degree isogeny arithmetic computations using the compressed Z value.

In one embodiment, an apparatus includes a hardware accelerator to execute cryptography operations including a Rivest Shamir Adleman (RSA) operation and an elliptic curve cryptography (ECC) operation. The hardware accelerator may include a multiplier circuit comprising a parallel combinatorial multiplier, and an ECC circuit coupled to the multiplier circuit to execute the ECC operation. The ECC circuit may compute a prime field multiplication using the multiplier circuit and reduce a result of the prime field multiplication in a plurality of addition and subtraction operations for a first type of prime modulus. The hardware accelerator may execute the RSA operation using the multiplier circuit. Other embodiments are described and claimed.

The invention relates to efficient zero knowledge verification of composite statements that involve both arithmetic circuit satisfiability and dependent statements about the validity of public keys (key-statement proofs) simultaneously. The method enables a prover to prove this particular statement in zero-knowledge. More specifically, the invention relates to a computer-implemented method for enabling zero-knowledge proof or verification of a statement (S) in which a prover proves to a verifier that a statement is true while keeping a witness (W) to the statement a secret. The invention also relates to the reciprocal method employed by a verifier who verifies the proof. The method includes the prover sending to the verifier a statement (S) having an arithmetic circuit with m gates and n wires configured to implement a function circuit and determine whether for a given function circuit output (h) and an elliptic curve point (P), the function circuit input (s) to a wire of the function circuit is equal to the corresponding elliptic curve point multiplier(s). The prover also sends individual wire commitments and/or a batched commitment for wires of the circuit, an input for a wire in the arithmetic circuit; and a function circuit output (h). The prover receives from the verifier a challenge value (x) and responding with an opening or additionally sends a proving key (PrK) to the verifier. The statement and the data enables the verifier to determine that the circuit is satisfied and calculate the elliptic curve point (P) and validate the statement, thus determining that the prover holds the witness (W) to the statement.

An apparatus and method for performing operation being secure against side channel attack are provided. The apparatus and method generate values equal to values obtained through an exponentiation operation or a scalar multiplication operation of a point using values extracted from previously generated parameter candidate value sets and an operation secure against side-channel attack, thereby improving security against side-channel attack without degrading performance.

Systems and methods described herein relate to techniques in which multiple parties each generate and exchange quantities that are based on a shared secret (e.g., powers of the shared secret) without exposing the shared secret. According to a protocol, two or more parties may exchange sets of elliptic curve points generated over polynomials that can be used, by each of the two or more parties, to determine a power of a shared secret. The protocol may be utilised as part of determining parameters for a smart contract that is broadcast to a blockchain network (e.g., Bitcoin). Based on the protocol, an additional party (e.g., a third party different from the two or more parties) may perform a computational task such as execution of the smart contract.

Systems and methods described herein relate to techniques that allow for multiple parties to jointly generate or jointly agree upon the parameters for generation of a smart contract, such as a verification key. Execution of the smart contract may be performed by a third party, for example, a worker node on a blockchain network. Techniques described herein may be utilised as part of a protocol in which parties of a smart contract share powers of a secret in a manner that allows each party to determine an identical common reference string, agree on parameters for a smart contract agree and/or make proportionate contributions the smart contract, and combinations thereof. The smart contract may be published to a blockchain network (e.g., Bitcoin Cash). The protocol may be a zero-knowledge protocol.

In one embodiment, an apparatus includes: a hardware accelerator to execute cryptography operations including a Rivest Shamir Adleman (RSA) operation and an elliptic curve cryptography (ECC) operation. The hardware accelerator may include: a multiplier circuit comprising a parallel combinatorial multiplier; and an ECC circuit coupled to the multiplier circuit to execute the ECC operation. The ECC circuit may compute a prime field multiplication using the multiplier circuit and reduce a result of the prime field multiplication in a plurality of addition and subtraction operations for a first type of prime modulus. The hardware accelerator may execute the RSA operation using the multiplier circuit. Other embodiments are described and claimed.

The invention relates to efficient zero knowledge verification of composite statements that involve both arithmetic circuit satisfiability and dependent statements about the validity of public keys (key-statement proofs) simultaneously. The method enables a prover to prove this particular statement in zero-knowledge. More specifically, the invention relates to a computer-implemented method for enabling zero-knowledge proof or verification of a statement (S) in which a prover proves to a verifier that a statement is true while keeping a witness (w) to the statement a secret. The invention also relates to the reciprocal method employed by a verifier who verifies the proof. The method includes the prover sending to the verifier a set of data including a statement, which for a given function circuit output and an elliptic curve point, the function circuit input is equal to the corresponding elliptic curve point multiplier. The data includes individual wire commitments and/or a batched commitment for the circuit of the statement, an input and an output. The prover can include in the data, or have shared in advance, the specification of the or each elliptic curve used in the statement. The prover then sends an opening, in response to a challenge from the verifier. Alternatively, the prover additionally includes a proving key. With the data received from the prover, the verifier is able to determine that the circuit is satisfied and calculate the elliptic curve point and validate the statement, thus determining that the prover holds the witness to the statement. Upon receiving the data the verifier determines through calculations that the data complies with the statement.