Method and system for encryption

A validating and authenticating method comprising:

• receiving a message M;
• receiving a request for validation and authentication;
• receiving an image PM of the message M captured using a user imaging device;
• analysing the received image PM to:
• determine if the image is valid by determining whether the received image PM comprises a digital fingerprint matching one of one or more digital fingerprints stored in a memory, wherein said one or more digital fingerprints are associated with user imaging devices, and the one or more digital fingerprints are each based on a photo response non-uniformity (PRNU) associated with a corresponding one of the user imaging devices;
• and
• determine if the image is authentic by extracting data from the received image PM and comparing the extracted data with the message M;
• and
• generating, if the image is valid and authentic, a response to the request.

A method of generating a digital signature, the method comprising:

• receiving a request to create a signature for an electronic message MF;
• generating a validation challenge comprising the electronic message M which is based on message MF;
• receiving the electronic message M;
• receiving a request for validation and authentication;
• validating and authenticating by:
• receiving an image PM of the electronic message M from a user;
• analysing the received image PM to:
• determine if the image is valid by determining whether the received image PM comprises a digital fingerprint matching one of one or more digital fingerprints stored in a memory, wherein said one or more digital fingerprints are associated with user imaging devices, and the one or more digital fingerprints are each based on a photo response non-uniformity (PRNU) associated with a corresponding one of the user imaging devices;
• and
• determine if the image is authentic by extracting data from the received image PM and comparing the extracted data with the message M;
• generating a validation response confirming that the received image PM is valid and authentic;
• and
• generating the signature for the electronic message MF.

A non-transitory data carrier carrying processor control code which when running on a processor, causes the processor to implement a method for validating and authenticating comprising the steps of:

• receiving a message M;
• receiving a request for validation and authentication;
• receiving an image PM of the message M captured using a user imaging device;
• analysing the received image PM to:
• determine if the image is valid by determining whether the received image PM comprises a digital fingerprint matching one of one or more digital fingerprints stored in a memory, wherein said one or more digital fingerprints are associated with user imaging devices, and the one or more digital fingerprints are each based on a photo response non-uniformity (PRNU) associated with a corresponding one of the user imaging devices;
• and
• determine if the image is authentic by extracting data from the received image PM and comparing the extracted data with the message M;
• and
• generating, if the image is valid and authentic, a response to the request.

A system for generating a digital signature on behalf of a user, the system comprising:

• a signature server;
• a memory storing one or more digital fingerprints associated with user imaging devices, wherein the one or more digital fingerprints are each based on a photo response non-uniformity (PRNU) associated with a corresponding one of the user imaging devices;
• a communication module configured to:
• receive a request to create a signature for an electronic message MF;
• receive an electronic message M, which is based on the electronic message MF;
• receive a request for validation and authentication;
• and
• receive an image PM of the electronic message M from a user;
• and
• an image validation module for analysing the received image PM to determine if the image is valid by determining whether the received image PM comprises a digital fingerprint matching one of the one or more digital fingerprints stored in the memory and to determine if the received image PM is authentic by extracting data from the received image PM and comparing the extracted data with the message M,
• wherein, if the received image PM is determined to be authentic and valid, the signature server generates a digital signature for the electronic message MF.