E-Lottery Scheme Without A Trusted Third Party

E-lottery scheme is a lottery scheme, based on cryptography, which employs computer and network technologies. E-lottery scheme can't only save much manpower and material resource in organization, selling lotteries and drawing a lottery, but also prevent the factitious factors in the scheme. Comparing with the traditional lottery scheme, the e-lottery scheme is more impartial, more secure and more efficient. Therefore, it is important to research e-lottery.Since Rivest RL and his partners introduced the first e-lottery scheme, the concept of e-lottery scheme is coming close to cryptography. But existing e-lottery schemes are of much weakness. Therefore, this thesis mainly study and introduce a new e-lotteries scheme. Based on bit commitment, the new e-lottery scheme does not assume all the purchasers are online, overcome the limitation of the purchasers'computing power and need not involve a trusted third party. There are many security properties in this scheme, such as unforgeable, impartiality, publicly verification and so on. This scheme also maintains compatibility with the traditional lottery.First, this thesis introduces the basic theory of cryptography involving in the e-lottery scheme, makes a brief introduction on the natures of the secure electronic voting scheme, then proposes a new e-lottery scheme. The new e-lottery scheme, which need not involve a trusted third party, gives the corresponding solution for the two mainstream kinds of traditional lotteries. This thesis also gives the safety analysis, efficiency analysis and compatibility analysis.