Search Patents
  • Prime field elliptic curve cryptography processor
    Patent number: 9002001
    Abstract: A system including a processor, a field addition circuit, and a field multiplication circuit. The processor is configured to execute instructions for performing elliptic curve operations on data. The elliptic curve operations include field operations performed in a prime field. The field addition circuit is configured to perform a field addition on the data in the prime field in response to the instructions requiring the field addition. The field multiplication circuit is configured to perform a field multiplication on the data in the prime field in response to the instructions requiring the field multiplication.
    Type: Grant
    Filed: January 22, 2013
    Date of Patent: April 7, 2015
    Assignee: Marvell International Ltd.
    Inventors: Fei Sun, Chang Shu
  • Short message encryption
    Patent number: 8503679
    Abstract: A method and system for securely communicating information via a low bandwidth channel uses encryption that adds comparatively little overhead to the size of the transmission. This method and system efficiently take advantage of the properties of public key cryptography, a shared secret, a traffic key from the shared secret, an abbreviated initialization vector, and an abbreviated whole message signature. The information and the whole message signature are encrypted using the traffic key with a stream cipher.
    Type: Grant
    Filed: January 23, 2008
    Date of Patent: August 6, 2013
    Assignee: The Boeing Company
    Inventor: Larry Bugbee
  • Constant time secure arithmetic-to-Boolean mask conversion
    Patent number: 11822704
    Abstract: A first arithmetic input share and a second arithmetic input share of an initial arithmetically-masked cryptographic value are received. A sequence of operations using the arithmetic input shares and a randomly generated number is performed, where a current operation in the sequence of operations generates a corresponding intermediate value that is used in a subsequent operation. At the end of the sequence of operations, a first Boolean output share and a second Boolean output share are generated. The arithmetic-to-Boolean mask conversion is independent of the input bit length.
    Type: Grant
    Filed: October 28, 2019
    Date of Patent: November 21, 2023
    Assignee: CRYPTOGRAPHY RESEARCH, INC.
    Inventors: Michael Hutter, Michael Tunstall
  • Method of securely implementing a cryptography algorithm of the RSA type, and a corresponding component
    Patent number: 7359508
    Abstract: A method for the secure application of a cryptographic algorithm of the RSA type in an electronic component obtains the value of a public exponent e from a given set of probable values, without a priori knowledge of that value. Having determined the value for the public exponent e, the application of countermeasures using the value of e, to block error attacks and side channel attacks, particularly of the DPA and SPA type, are carried out on the application of a private operation of the cryptographic algorithm.
    Type: Grant
    Filed: July 8, 2004
    Date of Patent: April 15, 2008
    Assignee: Gemplus
    Inventors: Karine Villegas, Marc Joye, Benoit Chevallier-Mames
  • Multi-dimensional montgomery ladders for elliptic curves
    Patent number: 8958551
    Abstract: An algorithm is provided having a matrix phase and point addition phase that permits computation of the combination of more than two point multiples. The algorithm has particular utility in elliptic curve cryptography (ECC) such as for computing scalar multiplications in, e.g. batch ECC operations, accelerating Lenstra's ECM factoring algorithm, exploiting expanded ECC certificates (which contain pre-computed multiples of a party's public key), incremental hashing based on elliptic curves, accelerating verification of ECDSA signatures, etc.
    Type: Grant
    Filed: June 25, 2008
    Date of Patent: February 17, 2015
    Assignee: Certicom Corp.
    Inventor: Daniel R. Brown
  • Generating genus 2 curves from invariants
    Patent number: 8457305
    Abstract: One or more techniques and/or systems are disclosed for generating a genus 2 curve for use in cryptography. One or more invariant values used to generate the genus 2 curve are determined by evaluating one or more invariant functions on a Hilbert modular surface. The genus 2 curve is generated using the one or more invariant values to determine an equation describing the genus 2 curve. A group is generated from the genus 2 curve, and the group may be used for a cryptographic application.
    Type: Grant
    Filed: November 13, 2009
    Date of Patent: June 4, 2013
    Assignee: Microsoft Corporation
    Inventors: Kristin Lauter, Tonghai Yang
  • Method and system for determining sequence parameters to limit cycle attacks in timed release cryptography
    Publication number: 20040264692
    Abstract: A method and system for determining sequence parameters to limit cycle attack in time-line sequences associated with digital signature technologies is disclosed. The method comprises the steps of determining a pair of values associated with a modulus value for generating said sequence, wherein said values are non-equal prime numbers of a known size, selecting a root value of said sequence and selecting a third value for determining the order of said sequence. In one aspect of the invention, each of the pair of values used to determine the modulus is a safe prime number.
    Type: Application
    Filed: June 30, 2003
    Publication date: December 30, 2004
    Inventors: Juan A. Garay, Carl B. Pomerance
  • Scalable key agile cryptography
    Patent number: 5796836
    Abstract: A system and method for encrypting blocks of plain text. Output FIFO memories are provided for decoupling pseudorandom vector generation from plain text encryption. The output FIFOs produce the effect of multiplexing several cryptographic devices together and can be combined with feedback FIFO memories in order to provide key agility and parallel secret key encryption. Throughput is also enhanced by constructing wide codebooks so that a block of data can be enciphered as a whole.
    Type: Grant
    Filed: August 29, 1995
    Date of Patent: August 18, 1998
    Assignee: Secure Computing Corporation
    Inventor: Thomas R. Markham
  • LOW-COMPLEXITY ELECTRONIC CIRCUIT PROTECTED BY CUSTOMIZED MASKING
    Publication number: 20130129081
    Abstract: A cryptography circuit protected by masking, said circuit including means for encrypting binary words using at least one key krc, means for applying linear processing operations and nonlinear processing operations to said words and means for masking said words. The binary words are unmasked upstream of the nonlinear processing operations by using a mask kri and masked downstream of said processing operations by using a mask kr+1i, the masks kri and kr+1i being chosen from a set of masks that is specific to each instance of the circuit.
    Type: Application
    Filed: November 8, 2010
    Publication date: May 23, 2013
    Applicant: INSTITUT TELECOM-TELECOM PARISTECH
    Inventors: Sylvain Guillet, Jean-Luc Danger
  • Protecting modular inversion operation from external monitoring attacks
    Patent number: 11418334
    Abstract: Systems and methods for performing modular inversion operations in a manner protected from external monitoring attacks. An example method comprises: determining, by a processor, a first masked value based on a public cryptographic key and a first random integer value; determining a second masked value based on the public cryptographic key and a second random integer value, and determining, based on the first masked value and the second masked value, a private cryptographic key represented by a modular inversion of the public cryptographic key.
    Type: Grant
    Filed: October 8, 2018
    Date of Patent: August 16, 2022
    Assignee: Cryptography Research, Inc.
    Inventors: Michael Alexander Hamburg, Michael Tunstall
  • Decryption apparatus and method of decrypting ciphertext of the same
    Patent number: 8781113
    Abstract: The method of decrypting a ciphertext includes: pre-storing a plurality of polynomial functions into which a secret key decrypting a ciphertext to a plaintext according to a public-key cryptography algorithm is broken down; receiving the ciphertext generated based on the secret key which is broken down into the plurality of polynomial functions from a ciphertext generating device; and decrypting the received ciphertext into the plaintext based on the pre-stored polynomial functions.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: July 15, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Yong-kuk You, Hee-jae Park, Jong-ho Rhee
  • Systems and methods for authentication based on physically unclonable functions
    Patent number: 9621359
    Abstract: Presented are systems, devices, and methods for reliably authenticating asymmetric cryptography-based ICs based on Physically Unclonable Functions (PUFs) that are immune to reverse engineering. Various embodiments of the invention enhance the level of security in IC architectures without the need to connect to a remote certification authority, thereby, eliminating shortfalls associated with online authentication. Certain embodiments accomplish this by using a PUF-generated secure private key that need never be output by or exported from the PUF.
    Type: Grant
    Filed: September 1, 2015
    Date of Patent: April 11, 2017
    Assignee: Maxim Integrated Products, Inc.
    Inventors: Christophe Tremlet, Scott Edward Jones
  • Multi-dimensional montgomery ladders for elliptic curves
    Patent number: 8750500
    Abstract: An algorithm is provided having a matrix phase and point addition phase that permits computation of the combination of more than two point multiples. The algorithm has particular utility in elliptic curve cryptography (ECC) such as for computing scalar multiplications in, e.g. batch ECC operations, accelerating Lenstra's ECM factoring algorithm, exploiting expanded ECC certificates (which contain pre-computed multiples of a party's public key), incremental hashing based on elliptic curves, accelerating verification of ECDSA signatures, etc.
    Type: Grant
    Filed: March 21, 2012
    Date of Patent: June 10, 2014
    Assignee: Certicom Corp.
    Inventor: Daniel Richard Brown
  • Method of securely implementing a cryptography algorithm of the RSA type, and a corresponding component
    Patent number: 7860242
    Abstract: A method for the secure application of a cryptographic algorithm of the RSA type in an electronic component obtains the value of a public exponent e from a given set of probable values, without a priori knowledge of that value. Having determined the value for the public exponent e, the application of countermeasures using the value of e, to block error attacks and side channel attacks, particularly of the DPA and SPA type, are carried out on the application of a private operation of the cryptographic algorithm.
    Type: Grant
    Filed: February 22, 2008
    Date of Patent: December 28, 2010
    Assignee: Gemalto SA
    Inventors: Karine Villegas, Marc Joye, Benoit Chevallier-Mames
  • Method for steganographic cryptography
    Patent number: 7646868
    Abstract: Methods for encrypting a clear text message into hidden cipher text are disclosed. Embodiments of the present invention may be used to encrypt clear text into a contextual altered form that does not appear to an observer to be cipher text. Embodiments of the present invention produce encrypted text without using a mathematical model of prime number factorization. Embodiments of the present invention provide better security by producing better quality cipher text output than known linguistic steganography approaches.
    Type: Grant
    Filed: August 29, 2006
    Date of Patent: January 12, 2010
    Assignee: Intel Corporation
    Inventor: Robert Vaughn
  • White-box elliptic curve point multiplication
    Patent number: 10068070
    Abstract: A method of obscuring software code implementing an elliptic curve cryptography (ECC) point multiplication function, including: receiving ECC parameters including a multiplier d having N bits; transforming multiplier d into an array d(i) with ?1, 0, and +1 values while maintaining the same value for d; and generating ECC point multiplication function operations using the transformed multiplier array d(i) and N, wherein the generated ECC point multiplication function operations are split variable operations.
    Type: Grant
    Filed: July 31, 2015
    Date of Patent: September 4, 2018
    Assignee: NXP B.V.
    Inventors: Jan Hoogerbrugge, Wil Michiels, Pim Vullers
  • MIX-NET SYSTEM
    Publication number: 20120250855
    Abstract: Each participant apparatus (103) encrypts a plaintext by using a secret key of secret key cryptography, encrypts the encryption key by a public key, and sends the plaintext and public key to a substitution/decryption apparatus (112). With this processing, the limitation on the length of a ciphertext to be processed can be eliminated. In this invention, a verifiable proof text using a public key by each substitution/decryption apparatus is verified by a verification apparatus (109) by using the public key. If one of a plurality of organizations to decrypt and shuffle ciphertexts has not correctly executed the operation, a third party can specify it and prove that the specified organization is unauthorized.
    Type: Application
    Filed: June 8, 2012
    Publication date: October 4, 2012
    Applicant: NEC CORPORATION
    Inventors: Jun Furukawa, Kazue Sako
  • Method and system for determining sequence parameters to limit cycle attacks in timed release cryptography
    Patent number: 7302056
    Abstract: A method and system for determining sequence parameters to limit cycle attack in time-line sequences associated with digital signature technologies is disclosed. The method comprises the steps of determining a pair of values associated with a modulus value for generating said sequence, wherein said values are non-equal prime numbers of a known size, selecting a root value of said sequence and selecting a third value for determining the order of said sequence. In one aspect of the invention, each of the pair of values used to determine the modulus is a safe prime number.
    Type: Grant
    Filed: June 30, 2003
    Date of Patent: November 27, 2007
    Assignee: Lucent Technologies Inc.
    Inventors: Juan A. Garay, Carl B. Pomerance
  • Using cryptographic blinding for efficient use of Montgomery multiplication
    Patent number: 11522669
    Abstract: Aspects of the present disclosure involves receiving an input message, generating a first random value that is used to blind the input message input message to prevent a side-channel analysis (SCA) attack, computing a second random value using the first random value and a factor used to compute the Montgomery form of a blinded input message without performing an explicit Montgomery conversion of the input message, and computing a signature using Montgomery multiplication, of the first random value and the second random value, wherein the signature is resistant to the SCA attack.
    Type: Grant
    Filed: March 26, 2019
    Date of Patent: December 6, 2022
    Assignee: CRYPTOGRAPHY RESEARCH, INC.
    Inventor: Michael Tunstall
  • METHOD TO CALCULATE SQUARE ROOTS FOR ELLIPTIC CURVE CRYPTOGRAPHY
    Publication number: 20140369492
    Abstract: A method is presented to compute square roots of finite field elements from the prime finite field of characteristic p over which points lie on a defined elliptic curve. Specifically, while performing point decompression of points that lie on a standardized elliptic curve over a prime finite field of characteristic 2224?296+1, the present method utilizes short Lucas sub-sequences to optimize the implementation of a modified version of Mueller's square root algorithm, to find the square root modulo of a prime number. The resulting method is at least twice as fast as standard methods employed for square root computations performed on elliptic curves.
    Type: Application
    Filed: June 18, 2013
    Publication date: December 18, 2014
    Inventor: Robert John LAMBERT