Hi, <br>proving that a message came from the owner of the private key usually refers to as proof of origin.<br><br>First question: is proof of origin the same as authenticity ? I would say so.<br><br>Second question: does authenticity provide non-repudiation ? I wouldn't say so. <br>
<br>Thinking about it I would say that non-repudiation does not just neeed proof of origin of the message but additionally the message must have not been tampered with while in transit. Following this line of reasoning private key encryption would not be enough to provide non-repudiation but actually digital signature is needed (one-way hash of a message, THEN the message is encrypted with the sender's private key).<br>
<br>Correct ?<br><br>Thanks,<br>Andrea<br>