Patents Assigned to Guardtime AS
  • Publication number: 20120324229
    Abstract: A method of generating a keyless digital multi-signature is provided. The method includes receiving multiple signature generation requests from one or more client computers, building subtrees based on the signature generation requests, and constructing a search tree including the subtrees. The method also includes assigning explicit length tags to leaf nodes of the search tree to balance the search tree and applying a hash function to each of the search tree nodes. The root hash value and the height of the search tree make up a generated aggregate signature request, followed by receiving an aggregate signature based on the aggregate signature request. The keyless digital multi-signature is generated based on the aggregate signature and contains an implicit length tag to verify that the number of signature generation requests is limited. The aggregate signature is generated if the height of the search tree does not exceed a predetermined height limitation.
    Type: Application
    Filed: June 20, 2011
    Publication date: December 20, 2012
    Applicant: GUARDTIME IP HOLDINGS LIMITED
    Inventors: Ahto Buldas, Andres Kroonmaa, Märt Saarepera
  • Patent number: 8312528
    Abstract: A system and method for generating a digital certificate is provided wherein a new digital record is received and is assigned a sequence value. A first composite digital value is generated by applying a first deterministic function to the digital records stored in a repository. The sequence value and first composite digital value are included in a first certificate. After the digital record is added to the repository, a second composite digital value is generated by applying a second deterministic function to the digital records in the repository. This second composite digital value, and a composite sequence value, are published. An interval digital value which is based upon the first and second composite digital values, and the sequence value, are included in a second certificate which thus verifies the authenticity and sequence value of the digital record.
    Type: Grant
    Filed: January 29, 2010
    Date of Patent: November 13, 2012
    Assignee: Guardtime IP Holdings Limited
    Inventors: Mart Saarepera, Ahto Buldas
  • Publication number: 20100199342
    Abstract: A system and method for generating a digital certificate is provided wherein a new digital record is received and is assigned a sequence value. A first composite digital value is generated by applying a first deterministic function to the digital records stored in a repository. The sequence value and first composite digital value are included in a first certificate. After the digital record is added to the repository, a second composite digital value is generated by applying a second deterministic function to the digital records in the repository. This second composite digital value, and a composite sequence value, are published. An interval digital value which is based upon the first and second composite digital values, and the sequence value, are included in a second certificate which thus verifies the authenticity and sequence value of the digital record.
    Type: Application
    Filed: January 29, 2010
    Publication date: August 5, 2010
    Applicant: GUARDTIME AS
    Inventors: Mart Saarepera, Ahto Buldas
  • Publication number: 20100199087
    Abstract: A system and method for generating a digital certificate is provided wherein a new digital record is received and is assigned a sequence value. A first composite digital value is generated by applying a first deterministic function to the digital records stored in a repository. The sequence value and first composite digital value are included in a first certificate. After the digital record is added to the repository, a second composite digital value is generated by applying a second deterministic function to the digital records in the repository. This second composite digital value, and a composite sequence value, are published. An interval digital value which is based upon the first and second composite digital values, and the sequence value, are included in a second certificate which thus verifies the authenticity and sequence value of the digital record.
    Type: Application
    Filed: January 29, 2010
    Publication date: August 5, 2010
    Applicant: GUARDTIME AS
    Inventors: Mart Saarepera, Ahto Buldas
  • Patent number: 7698557
    Abstract: A system and method for generating a digital certificate is provided wherein a new digital record is received and is assigned a sequence value. A first composite digital value is generated by applying a first deterministic function to the digital records stored in a repository. The sequence value and first composite digital value are included in a first certificate. After the digital record is added to the repository, a second composite digital value is generated by applying a second deterministic function to the digital records in the repository. This second composite digital value, and a composite sequence value, are published. An interval digital value which is based upon the first and second composite digital values, and the sequence value, are included in a second certificate which thus verifies the authenticity and sequence value of the digital record.
    Type: Grant
    Filed: December 7, 2004
    Date of Patent: April 13, 2010
    Assignee: Guardtime AS
    Inventors: Mart Saarepera, Ahto Buldas