Search Patents
  • 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
  • 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
  • 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 authenticating objects identified by images or other identifying information
    Patent number: 5351302
    Abstract: The method and system of the present invention utilizes public-key cryptography to create "secure" titles for personal and real property such as vehicles and the like. The title preferably comprises a card in which is stored a digital signature of one or more identifiers such as a vehicle identification number, the vehicle license plate and the owner's name. To effect a transfer of the property, the digital signature on the title must first be shown to have been generated from the one or more identifiers.
    Type: Grant
    Filed: May 26, 1993
    Date of Patent: September 27, 1994
    Inventors: Frank T. Leighton, Silvio Micali
  • Elliptic curve cryptography scheme with simple side-channel attack countermeasure
    Patent number: 11128434
    Abstract: There is provided an elliptic curve cryptographic scheme for permitting secure communications between two or more cryptographic correspondent devices, with a simple side-channel attack countermeasure. The cryptographic scheme includes: transforming a point to Jacobian projective coordinates; constant-time scalar multiplication of the point by a parameter; and transforming the resultant of the scalar multiplication to affine coordinates. The scalar multiplication including: performing iteratively to the value of the parameter either one of: doubling of the point and multiplying any two random field elements; or mixed addition of the point.
    Type: Grant
    Filed: August 13, 2019
    Date of Patent: September 21, 2021
    Assignee: INFOSEC GLOBAL INC.
    Inventors: Vladimir Soukharev, Basil Hess
  • MIX-NET SYSTEM
    Publication number: 20100115285
    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: January 8, 2010
    Publication date: May 6, 2010
    Applicant: NEC CORPORATION
    Inventors: JUN FURUKAWA, KAZUE SAKO
  • Method of using symmetric cryptography for both data encryption and sign-on authentication
    Patent number: 10419223
    Abstract: Embodiments herein provide, for example, a method that includes downloading a symmetrically encrypted data block from a server, where the encrypted data block comprises a server-stored secondary password; decrypting the encrypted data block with a shared-symmetric key; signing onto at least one of a server or service using the server-stored secondary password; generating a secondary password, where the generated secondary password is different than the server-stored secondary password; and overwriting the server-stored secondary password with the generated secondary password.
    Type: Grant
    Filed: August 31, 2015
    Date of Patent: September 17, 2019
    Assignee: CYPH, INC.
    Inventor: Ryan Lester
  • Method and apparatus for asymmetric cryptosystem based on quasi-cyclic moderate density parity-check codes over GF(q)
    Patent number: 11201731
    Abstract: Methods and apparatus for code-based asymmetric cryptosystem using Quasi-Cyclic Moderate-Density Parity-Check (QC-MDPC) error correcting codes. Specifically, the method and apparatus generalizes the framework of (QC-MDPC) Code-Based (CB) cryptography from the binary domain (Galois Field of two elements) to an arbitrary size of Galois Field and provides an apparatus for implementing the cryptosystem with a simplified computational complexity of key generation, encryption, and decryption components of the cryptosystems and reduced sizes of the public and private security keys.
    Type: Grant
    Filed: August 30, 2018
    Date of Patent: December 14, 2021
    Assignee: Zenith Electronics LLC
    Inventors: Kyle Xingkai Bao, Nejib Ammar
  • Method to calculate square roots for elliptic curve cryptography
    Patent number: 9148282
    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: Grant
    Filed: June 18, 2013
    Date of Patent: September 29, 2015
    Assignee: Certicom Corp.
    Inventor: Robert John Lambert
  • System and methods for data encryption using public key cryptography
    Patent number: 5559889
    Abstract: An integrated circuit ("IC") chip is provided having both a public key cryptographic engine and a fuse array thereon. The fuse array is hardwired to the public key cryptographic engine and is encoded with a private key for use by the cryptographic engine. Specifically, prior to encapsulation of the IC chip, the fuse array is encoded using a laser ablation process. Upon encapsulation, the private key is permanently sealed and secured within the IC chip. The fuse array may also have a public key hash value and a serial number encoded therein.
    Type: Grant
    Filed: March 31, 1995
    Date of Patent: September 24, 1996
    Assignee: International Business Machines Corporation
    Inventors: Randall J. Easter, William A. Merz
  • Method and apparatus for perfect forward secrecy using deterministic hierarchy
    Patent number: 10574451
    Abstract: Method and apparatus for a system to communicate via perfect forward secrecy. A deterministic hierarchy is used to generate public and private keys, offline, on distinct devices, for use with asymmetrical cryptography over an unsecure medium. Because each private key is not transmitted over the unsecure medium, but must be used to de-encrypt the communications, it is very difficult for man-in-the-middle attacks to de-encrypt the communications. Because each private key is generated according to a deterministic hierarchy, a master entity can recreate the private keys and passively monitor the communications while maintaining perfect forward secrecy.
    Type: Grant
    Filed: October 19, 2017
    Date of Patent: February 25, 2020
    Assignee: Bank of America Corporation
    Inventors: Amanda Jane Adams, Ben Lightowler
  • System and methods for data encryption using public key cryptography
    Patent number: 5563950
    Abstract: An integrated circuit ("IC") chip is provided having both a public key cryptographic engine and a fuse array thereon. The fuse array is hardwired to the public key cryptographic engine and is encoded with a private key for use by the cryptographic engine. Specifically, prior to encapsulation of the IC chip, the fuse array is encoded using a laser ablation process. Upon encapsulation, the private key is permanently sealed and secured within the IC chip. The fuse array may also have a public key hash value and a serial number encoded therein.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: October 8, 1996
    Assignee: International Business Machines Corporation
    Inventors: Randall J. Easter, William A. Merz
  • Method and apparatus for perfect forward secrecy using deterministic hierarchy
    Patent number: 11177948
    Abstract: Method and apparatus for a system to communicate via perfect forward secrecy. A deterministic hierarchy is used to generate public and private keys, offline, on distinct devices, for use with asymmetrical cryptography over an unsecure medium. Because each private key is not transmitted over the unsecure medium, but must be used to de-encrypt the communications, it is very difficult for man-in-the-middle attacks to de-encrypt the communications. Because each private key is generated according to a deterministic hierarchy, a master entity can recreate the private keys and passively monitor the communications while maintaining perfect forward secrecy.
    Type: Grant
    Filed: January 24, 2020
    Date of Patent: November 16, 2021
    Assignee: Bank of America Corporation
    Inventors: Amanda Jane Adams, Ben Lightowler
  • Countermeasure to power attack and timing attack on cryptographic operations
    Patent number: 6804782
    Abstract: A cryptography circuit provides secure processing of data by utilizing countermeasures that combat timing and power attacks. Superfluous operations such as multiplication operations, modular reductions by an integer, storage of data to memory are available for use by a processor to disguise the amount of power usage and the amount of time required to perform a cryptographic operation. A cryptographic key is available for use in order to trigger when these emulated operations occur. The occurrences of the emulated operations is controlled by the user to provide the preferred tradeoff between security and use of resources.
    Type: Grant
    Filed: August 13, 1999
    Date of Patent: October 12, 2004
    Assignee: General Instrument Corporation
    Inventors: Xin Qiu, Eric J. Sprunk, Daniel Z. Simon, Lawrence Tang, Lawrence R. Cook
  • Leak-resistant cryptographic payment smartcard
    Publication number: 20030028771
    Abstract: We disclose methods and apparatuses for securing cryptographic devices against attacks involving external monitoring and analysis. A “self-healing” property is introduced, enabling security to be continually re-established following partial compromises. In addition to producing useful cryptographic results, a typical leak-resistant cryptographic operation modifies or updates secret key material in a manner designed to render useless any information about the secrets that may have previously leaked from the system. Exemplary leak-proof and leak-resistant implementations are shown for symmetric authentication, certified Diffie-Hellman (when either one or both users have certificates), RSA, ElGamal public key decryption.
    Type: Application
    Filed: April 29, 2002
    Publication date: February 6, 2003
    Applicant: Cryptography Research, Inc.
    Inventors: Paul C. Kocher, Joshua M. Jaffe
  • Online/offline signature system and method based on multivariate cryptography
    Patent number: 10623189
    Abstract: Disclosed is an offline/online signature system including a key distribution center (KDC) and a signature end, wherein the KDC includes a key generating module, an offline signature module, and a verification module; and the signature end includes an online signature module and a verification module. The key generating module generates a temporary signature required for online signature, and transmits the result to a sensor node for storage. The online signature module generates a signature for a specific message; and the verification module includes a processor and a public key transformation component, wherein the processor transmits the signature to the public key transformation component and determines whether the signature is valid.
    Type: Grant
    Filed: December 23, 2015
    Date of Patent: April 14, 2020
    Assignee: South China University of Technology
    Inventors: Shaohua Tang, Jiahui Chen
  • Method and apparatus for dual hardware and software cryptography
    Patent number: 7120799
    Abstract: The present invention provides a method, apparatus, and computer implemented instructions for executing cryptographic operations. Responsive to a request to perform a cryptographic operation, one (or more) of a software process and a hardware process is selected for performing the cryptographic operation based on a policy which process results with available resources to perform the cryptographic operation to form a selected process. The cryptographic operation is performed using the selected process. Necessary object conversions, which is transparent to the application, is carried out in order to convert objects to usable forms of the selected process(es).
    Type: Grant
    Filed: December 15, 2000
    Date of Patent: October 10, 2006
    Assignee: International Business Machines Corporation
    Inventors: Lok Yan Leung, Anthony Joseph Nadalin, Bruce Arland Rich, Theodore Jack London Shrader
  • Mix-net system
    Patent number: 8583925
    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: Grant
    Filed: June 8, 2012
    Date of Patent: November 12, 2013
    Assignee: NEC Corporation
    Inventors: Jun Furukawa, Kazue Sako
  • Cryptosystems using commuting pairs in a monoid
    Patent number: 7136484
    Abstract: Apparati, methods, and computer readable media for enabling two parties (1,2) to exchange encrypted messages, exchange symmetric cryptographic keys, and perform functions of public key cryptography. First and second key exchange algorithms use commuting pairs of subsets of a monoid. The first key exchange algorithm has four principal embodiments. In three of the embodiments, a set of matrices over a hyperbolic ring is used as the monoid. In the fourth embodiment, a braid group is used as the monoid. The second key exchange algorithm has five principal embodiments. In four of the embodiments, a set of matrices over a hyperbolic ring is used as the monoid. In the fifth embodiment, a braid group is used as the monoid.
    Type: Grant
    Filed: April 24, 2002
    Date of Patent: November 14, 2006
    Assignee: Silicon Image, Inc.
    Inventor: Jee H. Koh
  • Public-private key pair account login and key manager
    Patent number: 10924289
    Abstract: Embodiments of the invention provide improved account authentication using public-private key cryptography instead of passwords. Instead of registering a password and using that password to login to an account, an authentication server of an account provider registers a public key received from a user device. To authenticate the user device for logging into an account, the authentication server generates a challenge and encrypts using the registered public key. The encrypted challenge is sent to the user device, which can decrypt the challenge using the private key corresponding to the registered public key. The decrypted challenge is used for authentication instead of using a password. The private key corresponding to the public key is securely stored and not revealed to the authentication server.
    Type: Grant
    Filed: July 13, 2018
    Date of Patent: February 16, 2021
    Assignee: Visa International Service Association
    Inventor: Robert Chumbley