A Fail-Stop Blind Proxy Signature And Its Application In Electronic Voting

Traditional cryptographic protocols are mostly constructed on the hardness of some computational problems, e.g. Integer Factoring Problem and Discrete Logarithm Problem, etc. Security based on these problems are called Computational Security. It means that when attacker has unbounded computational resources, these protocols are no more safe. Though the scenario of solving hard problems are not necessarily true in the real life, nevertheless people become less and less confident in the secu-rity based on these hard problems. The reasons behind these concerns vary from the extraordinary progress in the hardware, to the fast advances in the algorithms, to the existence of powerful secret government agents. With these concerns, "Unconditional Security" becomes once again the hot topic in the cryptography. Unconditional Se-curity, or Information Theoretic Security, are based on of course Information Theory (i.e. Probability Theory). This kind of security are against attackers with unbounded computational resources. In our paper, we added Proxy and Blind to a Fail-Stop Signa-ture, and achieved a new signature scheme called Fail-Stop Blind Proxy Signature. It is firstly computationally secure as other ordinary signature scheme since it is based on Discrete Logarithm Problem. It is also unconditionally secure because of the Fail-Stop property. So even the signature forger are with unbounded computational resources so that he can indeed forge a valid signature, the honest signer can prove with over-whelming probability that the signature is a fake one. We later integrate our much safer signature scheme into the Electronic Voting which demands high security. With the help of other unconditional secure protocols we succeeded in constructing a new unconditionally secure Electronic Voting system which is safer than ordinary E-Voting systems.