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Wajdi K. Feghali, Boston US

Wajdi K. Feghali, Boston, MA US

Patent application numberDescriptionPublished
20080240421Method and apparatus for advanced encryption standard (AES) block cipher - The speed at which encrypt and decrypt operations may be performed in a general purpose processor is increased by providing a separate encrypt data path and decrypt data path. With separate data paths, each of the data paths may be individually optimized in order to reduce delays in a critical path. In addition, delays may be hidden in a non-critical last round.10-02-2008
20080240422Efficient advanced encryption standard (AES) Datapath using hybrid rijndael S-Box - The speed at which an AES decrypt operation may be performed in a general purpose processor is increased by providing a separate decrypt data path. The critical path delay of the aes decrypt path is reduced by combining multiply and inverse operations in the Inverse SubBytes transformation. A further decrease in critical path delay in the aes decrypt data path is provided by merging appropriate constants of the inverse mix-column transform into a map function.10-02-2008
20080240426Flexible architecture and instruction for advanced encryption standard (AES) - A flexible aes instruction set for a general purpose processor is provided. The instruction set includes instructions to perform a “one round” pass for aes encryption or decryption and also includes instructions to perform key generation. An immediate may be used to indicate round number and key size for key generation for 128/192/256 bit keys. The flexible aes instruction set enables full use of pipelining capabilities because it does not require tracking of implicit registers.10-02-2008
20080304659METHOD AND APPARATUS FOR EXPANSION KEY GENERATION FOR BLOCK CIPHERS - A key scheduler performs a key-expansion to generate round keys for AES encryption and decryption just-in-time for each AES round. The key scheduler pre-computes slow operations in a current clock cycle to reduce the critical delay path for computing the round key for a next AES round.12-11-2008
20090003593UNIFIED SYSTEM ARCHITECTURE FOR ELLIPTIC-CURVE CRYTPOGRAPHY - A system for performing public key encryption is provided. The system supports mathematical operations for a plurality of public key encryption algorithms such as Rivert, Shamir, Aldeman (RSA) and Diffie-Hellman key exchange (DH) and Elliptic Curve Cryptosystem (ECC). The system supports both prime fields and different composite binary fields.01-01-2009
20090003594MODULUS SCALING FOR ELLIPTIC-CURVE CRYPTOGRAPHY - Modulus scaling applied a reduction techniques decreases time to perform modular arithmetic operations by avoiding shifting and multiplication operations. Modulus scaling may be applied to both integer and binary fields and the scaling multiplier factor is chosen based on a selected reduction technique for the modular arithmetic operation.01-01-2009
20090003595SCALE-INVARIANT BARRETT REDUCTION FOR ELLIPTIC-CURVE CYRPTOGRAPHY - The computation time to perform scalar point multiplication in an Elliptic Curve Group is reduced by modifying the Barrett Reduction technique. Computations are performed using an N-bit scaled modulus based a modulus m having k-bits to provide a scaled result, with N being greater than k. The N-bit scaled result is reduced to a k-bit result using a pre-computed N-bit scaled reduction parameter in an optimal manner avoiding shifting/aligning operations for any arbitrary values of k, N.01-01-2009
20090003596EFFICIENT ELLIPTIC-CURVE CRYPTOGRAPHY BASED ON PRIMALITY OF THE ORDER OF THE ECC-GROUP - Time to perform scalar point multiplication used for ECC is reduced by minimizing the number of shifting operations. These operations are minimized by applying modulus scaling by performing selective comparisons of points at intermediate computations based on primality of the order of an ECC group.01-01-2009
20090006511POLYNOMIAL-BASIS TO NORMAL-BASIS TRANSFORMATION FOR BINARY GALOIS-FIELDS GF(2m) - Basis conversion from polynomial-basis form to normal-basis form is provided for both generic polynomials and special irreducible polynomials in the form of “all ones”, referred to as “all-ones-polynomials” (AOP). Generation and storing of large matrices is minimized by creating matrices on the fly, or by providing an alternate means of computing a result with minimal hardware extensions.01-01-2009
20090006512NORMAL-BASIS TO CANONICAL-BASIS TRANSFORMATION FOR BINARY GALOIS-FIELDS GF(2m) - Basis conversion from normal form to canonical form is provided for both generic polynomials and special irreducible polynomials in the form of “all ones”, referred to as “all-ones-polynomials” (AOP). Generation and storing of large matrices is minimized by creating matrices on the fly, or by providing an alternate means of computing a result with minimal hardware extensions.01-01-2009
20090006517UNIFIED INTEGER/GALOIS FIELD (2m) MULTIPLIER ARCHITECTURE FOR ELLIPTIC-CURVE CRYTPOGRAPHY - A unified integer/Galois-Field 201-01-2009
20090019342Determining a Message Residue - A technique of determining a message residue includes accessing a message and simultaneously determining a set of modular remainders with respect to a polynomial for different respective segments of the message. The technique also includes determining a modular remainder with respect to the polynomial for the message based on the set of modular remainders and a set of constants determined prior to accessing the message. The modular remainder with respect to the polynomial for the message is stored in a memory.01-15-2009
20090089617METHOD AND APPARATUS FOR TESTING MATHEMATICAL ALGORITHMS - A method and apparatus for testing mathematical programs where code coverage is exceedingly difficult to hit with random data test vectors (probability <204-02-2009
20090164543APPARATUS AND METHOD TO COMPUTE RECIPROCAL APPROXIMATIONS - A method and apparatus for reducing memory required to store reciprocal approximations as specified in Institute of Electrical and Electronic Engineers (IEEE) standards such as IEEE 754 is presented. Monotonic properties of the reciprocal function are used to bound groups of values. Efficient bit-vectors are used to represent information in groups resulting in a very compact table representation about four times smaller than storing all of the reciprocal approximations in a table.06-25-2009
20090164546METHOD AND APPARATUS FOR EFFICIENT PROGRAMMABLE CYCLIC REDUNDANCY CHECK (CRC) - A method and apparatus to optimize each of the plurality of reduction stages in a Cyclic Redundancy Check (CRC) circuit to produce a residue for a block of data decreases area used to perform the reduction while maintaining the same delay through the plurality of stages of the reduction logic. A hybrid mix of Karatsuba algorithm, classical multiplications and serial division in various stages in the CRC reduction circuit results in about a twenty percent reduction in area on the average with no decrease in critical path delay.06-25-2009
20100332578Method and apparatus for performing efficient side-channel attack resistant reduction - A time-invariant method and apparatus for performing modular reduction that is protected against cache-based and branch-based attacks is provided. The modular reduction technique adds no performance penalty and is side-channel resistant. The side-channel resistance is provided through the use of lazy evaluation of carry bits, elimination of data-dependent branches and use of even cache accesses for all memory references.12-30-2010
20110145683Instruction-set architecture for programmable cyclic redundancy check (CRC) computations - A method and apparatus to perform Cyclic Redundancy Check (CRC) operations on a data block using a plurality of different n-bit polynomials is provided. A flexible CRC instruction performs a CRC operation using a programmable n-bit polynomial. The n-bit polynomial is provided to the CRC instruction by storing the n-bit polynomial in one of two operands.06-16-2011
20110153700Method and apparatus for performing a shift and exclusive or operation in a single instruction - Method and apparatus for performing a shift and XOR operation. In one embodiment, an apparatus includes execution resources to execute a first instruction. In response to the first instruction, said execution resources perform a shift and XOR on at least one value.06-23-2011
20110153993Add Instructions to Add Three Source Operands - A method in one aspect may include receiving an add instruction. The add instruction may indicate a first source operand, a second source operand, and a third source operand. A sum of the first, second, and third source operands may be stored as a result of the add instruction. The sum may be stored partly in a destination operand indicated by the add instruction and partly a plurality of flags. Other methods are also disclosed, as are apparatus, systems, and instructions on machine-readable medium.06-23-2011
20110153994Multiplication Instruction for Which Execution Completes Without Writing a Carry Flag - A method in one aspect may include receiving a multiply instruction. The multiply instruction may indicate a first source operand and a second source operand. A product of the first and second source operands may be stored in one or more destination operands indicated by the multiply instruction. Execution of the multiply instruction may complete without writing a carry flag. Other methods are also disclosed, as are apparatus, systems, and instructions on machine-readable medium.06-23-2011
20110161635Rotate instructions that complete execution without reading carry flag - A method of one aspect may include receiving a rotate instruction. The rotate instruction may indicate a source operand and a rotate amount. A result may be stored in a destination operand indicated by the rotate instruction. The result may have the source operand rotated by the rotate amount. Execution of the rotate instruction may complete without reading a carry flag.06-30-2011

Patent applications by Wajdi K. Feghali, Boston, MA US