Guardtime Sa

Denis Firsov

Ahto Truu

Henri Lakk

Digital signatures are generated for a message using an authentication tree data structure in which nodes are created as needed from a root node. A public and secret key pair is generated using a one-time signature method to form each node, and the secret key of each parent node is used to sign the public keys of its child nodes. Once the secret key of a node has been used in creating a signature for a message, it may be revealed. The signature data structure is unbounded and stateless, and need not be pre-generated and fixed.

Method and system for generating data signatures using an unbounded, stateless private key

Data security is provided in the form of a method for digitally signing a data message. A client device issues a issuing a signature request to a server and generates a first signature part as functions of selected ones of first signature parameters. It then receives from the server a second signature part, said second signature part having been computed by the server as functions of second signature parameters and at least one of the first signature parameters. The client device then attempts to verify components of the second signature part and generates a final digital signature of the message only if the components of the second signature part are valid. Part of the computational effort of creating the signature is thus offloaded to the server, even though the server may not be fully trusted.

Growing community of inventors

Tallinn, Estonia

Denis Firsov