Research On Information-theoretically Secure Secret-key Agreement

Information-theoretically secure secret-key agreement is the key to make perfect security. The models of unconditional security from quantum channels and noisy channels are two typical methods now. Two parties begin the secret-key agreement over a public channel. Such a secret-key agreement over a public channel usually consists of three phases, advantage distillation, information reconciliation and privacy amplification,but advantage distillation isn't required for the quantum secret-key agreement.The main work in this thesis is as follows: 1. Present a new composition protocol of the advantage distillation and advantage degeneration protocols in perfect secure scheme. Not only is its calculation the same simple as the bit pair iteration advantage distillation protocol, but also it is an advantaged degeneration, which make the privacy amplification to be easy even if the Eve's bit error rate is very low.2. Research how two parties, Alice and Bob, mutually check their knowledge of a common secret string in quantum secret key agreement. An efficient protocol based on the neighborhood collision free function is proposed.3. Use a two-party secret-key agreement system as an underlying cryptographic primitive and extend it to a conference system which is as secure as the two-party system.