Linkability in Practical Electronic Cash Design
Greg Maitland6
, Jason Reid6
, Ernest Foo6
, Colin Boyd6
and Ed Dawson6 
| (6) |
Information Security Research Centre, Queensland University of Technology, Brisbane, Australia |
Abstract
Designing a practical and complete electronic cash scheme has proved difficult. Designs must seek to optimise often conflicting
metrics such as efficiency, anonymity, the ability to make exact payments. Gains in one area often result in a loss in one
or more other areas. Several schemes have accepted linkability of some payments as a concession to getting the balance right.
A point that has not been highlighted is the problem of preventing linking between payments made with different linkable coins.
This paper reviews several electronic cash schemes which have the linkability property and concludes that linking across coins
is of significant practical concern. Design improvements are suggested along with observations regarding the user’s active
role in preserving anonymity.
This research is part of an ARC SPIRT project undertaken jointly by Queensland University of Technology and Telstra
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