Guardtime IP Holdings Limited

Michael Gault

Jeffrey Pearce

Ahto Buldas

Ahto Truu

Martin Ruubel

Andres Kroonmaa

Risto Laanoja

David F A Piesse

Jian Tan

Peter Rajnak

At least one node in a distributed hash tree verification infrastructure is augmented with an identifier of an entity in a registration path. A data signature, which includes parameters for recomputation of a verifying value, and which is associated with a digital input record, will therefore also include data that identifies at least one entity in the hash tree path used for its initial registration in the infrastructure. An uppermost value of the hash tree verification infrastructure is entered as, or as part of, a transaction in a blockchain.

Blockchain-supported, node ID-augmented digital record signature method

A code is added as a marking to a document and encodes an identifier that maps to a copy of the document stored in a database. Database copies of stored documents are preferably digitally signed. Using a device such as a smart phone, a user may extract the document identifier from the marking on a purported authentic version of the document and retrieve a copy of the document from the corresponding location in the database. The user can then visually compare the purported authentic version of the document with the retrieved database copy.

System and method for field-verifiable record authentication

A capture device such as a camera and/or sound recorder records an event, which includes a visual and/or audible presentation of a time value that is non-deterministic, yet a function of physical time. The non-deterministic time value (NDT) may be generated as a function of a calendar value created at time intervals as a root hash value of a distributed, hash-tree document authentication infrastructure. If the NDT value included in the recording of the event does not match the NDT value corresponding to the calendar value from which it was generated, the recording may be assumed to be altered. Digital time-stamping may be included for the recording of the event to reduce the opportunity for back-dating of the recording. NDT may also be generated simply for display by a clock, for example as an NDT time zone.

Non-deterministic time systems and methods

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Hong Kong, China

Michael Gault