Experimental demonstration of photonic quantum digital signatures

Digital signature schemes are often used in interconnected computer networks to verify the origin and authenticity of messages. Current classical digital signature schemes based on so-called "one-way functions" rely on computational complexity to provide security over sufficiently long timescales. However, there are currently no mathematical proofs that such functions will always be computationally complex. Quantum digital signatures offers a means of confirming both origin and authenticity of a message with security verified by information theoretical limits The message cannot be forged or repudiated. We have constructed, tested and analyzed the security of what is, to the best of our knowledge, the first example of an experimental quantum digital signature system.