Prepare and Measure Quantum Digital Signature: Difference between revisions

Digital Signatures (QDS) allow the exchange of classical messages from sender to multiple recipients, with a guarantee that the signature has come from a genuine sender. Additionally, it comes with the properties of (i) [[transferability]] i.e. messages with DS can be forwarded from one recipient to another such that DS is verifiable to have come from the original sender, (ii) [[non-repudiation]] i.e at any stage after sending the message to one recipient, sender cannot deny having sent the message and corresponding DS, and (iii) [[unforgeability]] i.e. a dishonest recipient cannot alter or fake the sender's DS and forward it to other recipients successfully. <br/>For simplicity, most protocols take into account the case of one sender and two recipients (Seller, buyer and verifier) exchanging single-bit classical messages. Such protocols require parties to prepare and measure quantum states instantly without having to store them.