Optionally moderated transaction systems

Patent 5276736 Issued on January 4, 1994. Estimated Expiration Date:

July 13, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Identity verification method and apparatus
Patent #: 4123747
Issued on: 10/31/1978
Inventor: Lancto , et al.

Encryption printed circuit board
Patent #: 4797928
Issued on: 01/10/1989
Inventor: Dykes

Card-computer moderated systems Patent #: 4926480
Issued on: 05/15/1990
Inventor: Chaum

Inventor

Chaum, David

Application

No. 912193 filed on 07/13/1992

US Classes:

705/69, Electronic cash detail (e.g., blinded, divisible, or detecting double spending)705/13, Transportation facility access (e.g., fare, toll, parking)705/74, Anonymous user system713/180Generating specific digital signature type (e.g., blind, shared, or undeniable)

Examiners

Primary: Buczinski, Stephen C.

Attorney, Agent or Firm

Nixon & Vanderhye

International Classes

H04k 001/00
H04L 009/02
H04L 009/00

Foreign Application Priority Data

1990-01-29 EP

Abstract

A tamper-resistant part is disclosed that can conduct transactions with an external system through a moderating user-controlled computer or that can on other occasions be brought into direct connection with the external system. In the moderated configuration, the moderating computer is able to ensure that certain transactions with the external system are unlinkable to each other. In the unmoderated configuration the tamper-resistant part can also ensure the unlinkability of certain transactions. Also testing configurations are disclosed that allow improper functioning of the tamper-resistant part, such as that which could link transactions, to be detected by user-controlled equipment. Another testing configuration can detect improper functioning of an external system that could, for instance, obtain linking information from a tamper-resistant part.