A technique based on public key cryptography is presented that allows an electronic mail system to hide who a participant communicates with as well as the content of the communication-in spite of an unsecured underlying telecommunication system. The technique does not require a universally trusted authority. One correspondent can remain anonymous to a… (More)
Keeping confidential who sends which messages, in a world where any physical transmission can be traced to its origin, seems impossible. The solution presented here is unconditionally or cryptographically secure, depending on whether it is based on one-time-use keys or on public keys, respectively. It can be adapted to address efficiently a wide variety of… (More)
It is often the case in applications of cryptographic protocols that one party would like to determine a practical upper-bound on the physical distance to the other party. For instance, when a person conducts a cryptographic identiication protocol at an entrance to a building, the access control computer in the building would like to be ensured that the… (More)
The large-scale automated transaction systems of the near future can be designed to protect the privacy and maintain the security of both individuals and organizations.
A new kind of receipt sets a far higher standard of security by letting voters verify the election outcome - even if all election computers and records were compromised. The system preserves ballot secrecy, while improving access, robustness, and adjucation, all at lower cost.
Previously there have been essentially only two models for computers that people can use to handle ordinary consumer transactions: (1) the tamper-proof module, such as a smart card, that the person cannot modify or probe; and (2) the personal workstation whose inner working is totally under control of the individual. The rst part of this article argues that… (More)
We present an election scheme designed to allow voters to verify that their vote is accurately included in the tabulation. The scheme provides a high degree of transparency whilst ensuring the secrecy of votes. Assurance is derived from close auditing of all the steps of the vote recording and counting process with minimal dependence on the system… (More)
Protocols are given for allowing a " prover " to convince a " verifier " that the prover knows some verifiable secret information, without allowing the verifier to learn anything about the secret. The secret can be probabilistically or deterministically verifiable, and only one of the prover or the verifier need have constrained resources. This paper… (More)