US 11,641,347 B2 · Quantum-safe cryptographic methods and systems

Abstract

Cryptographic methods and systems for key exchange, digital signature and zero-knowledge proof. In the digital signature scenario, there is provided a method of signing a digital document, comprising: obtaining a private cryptographic key associated with the signer; obtaining a digital asset from the digital document; selecting a base data element; computing a plurality of signature data elements from (i) the digital asset, (ii) the base data element and (iii) the private cryptographic key; and transmitting the digital document and the plurality of signature data elements to a recipient over a data network. Provenance of the digital document is confirmable by the recipient carrying out a predefined computation involving the digital document, the signature data elements, a plurality of noise variables and a public cryptographic key corresponding to the private cryptographic key associated with the signer. In the zero-knowledge proof scenario, the digital asset plays the role of a challenge data element.

Claims22

Dependent claims

A method of operating a computing apparatus to confirm provenance of a received message purportedly sent by a given sender, the message comprising a digital signature, the digital signature comprising a plurality of data elements, the method comprising:

obtaining a digital asset from the message;
obtaining a public cryptographic key of the given sender;
selecting a plurality of noise variables;
computing a plurality of data elements based on the digital asset, the noise variables and the public cryptographic key of the given sender;
evaluating whether the computed data elements and the data elements of the digital signature obey a predetermined relationship, the predetermined relationship being that AQ′is equal to a product of BP′, CN0, DNn and E, wherein A, B, C, D and E represent the data elements of the digital signature and wherein Q′, P′, N0 and Nn represent parts of the public cryptographic key;
in case the computed data elements and the data elements of the digital signature obey the predetermined relationship, generating a signal indicative of the message having been sent by the given sender, otherwise, generating a signal indicative of the message not having been sent by the given sender.

3 more elements

A non-transitory computer-readable storage medium comprising computer-readable instructions which, when executed by a processing entity of a computing apparatus, cause the computing apparatus to carry out operations to confirm provenance a received message purportedly sent by a given sender, the message comprising a digital asset and a digital signature, the digital signature comprising a plurality of data elements, the operations including:

obtaining a digital asset from the message;
obtaining a public cryptographic key of the given sender;
selecting a plurality of noise variables;
computing a plurality of data elements based on the digital asset, the noise variables and the public cryptographic key of the given sender;
evaluating whether the computed data elements and the data elements of the digital signature obey a predetermined relationship, the predetermined relationship being that AQ′is equal to the product of BP′, CN0, DNn and E, wherein A, B, C, D and E represent the data elements of the digital signature and wherein Q′, P′, N0 and Nn represent parts of the public cryptographic key;
in case the computed data elements and the data elements of the digital signature obey the predetermined relationship, generating a signal indicative of the message having been sent by the given sender, otherwise, generating a signal indicative of the message not having been sent by the given sender.

3 more elements

Dependencies are inferred from the claim text.

Quantum-safe cryptographic methods and systems

Life of this patent

Quantum-safe cryptographic methods and systems

Life of this patent

Abstract

Claims22