Fair E-Cash System for Internet Payment

In a fair e-cash system, the trustee holds the ability to revoke the anonymity of a user. Anonymity revocation means tracing where a user has spent the coins ( coin tracing) or tracing whom a spent coin belongs to ( owner tracing ) . The trustee is expected to revoke the anonymity of a user only whe...

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Main Author: Ching, Yen Choon
Format: Thesis
Published: 2001
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id my-mmu-ep.14
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spelling my-mmu-ep.142009-12-02T09:31:01Z Fair E-Cash System for Internet Payment 2001-06-14 Ching, Yen Choon HG1710 Electronic Funds Transfers In a fair e-cash system, the trustee holds the ability to revoke the anonymity of a user. Anonymity revocation means tracing where a user has spent the coins ( coin tracing) or tracing whom a spent coin belongs to ( owner tracing ) . The trustee is expected to revoke the anonymity of a user only when instructed by the court. This allows the law enforcement authority to catch users who use the e-cash for criminal activities while protecting the anonymity of those that do not misuse it. A fair e-cash system is called off-line if the trustee is only involved during the revocation process. Previous schemes required the tracing information to be constructed for each coins. This resulted in high computation during withdrawal time and the coin size is quite large. Thus, it is not suitable to be implemented on devices with limited memory or processing capability such as smart cards, PDAs or WAP phones. In this thesis, we proposed a different approach to construct an off-line fair e-cash system which resulted in a significant reduction in terms of computation and storage. We use what we call a license to achieve tracing. This license will contain the user's information which the trustee can extract out for tracing purposes. There is no monetary value associated with this license. The user must always present a valid license for every transaction. Since the tracing information is not constructed into the coin, the coin will have a simpler 'structure'. We still require the user to include his identity in the coin. However, the user does not need to prove that this is correctly done during withdrawal time. He only needs to show that the identity embedded in the coin is the same as the identity embedded in the license during payment time. This is to prevent the coins from being used by someone else except the withdrawer. Using this new approach , the coins vannot be traced directly. Instead, one has to trace the licenses withdrawn. This indirectly allows the law enforcement authority to trace the whereabouts of suspicious withdrawal. For the owner tracing, the tracing is accomplished using the license. The design is simple and direct. This allows us to easily analyze the security of the scheme and also to reduce implementation errors. 2001-06 Thesis http://shdl.mmu.edu.my/14/ http://vlib.mmu.edu.my/diglib/login/dlusr/login.php masters Multimedia University Research Library
institution Multimedia University
collection MMU Institutional Repository
topic HG1710 Electronic Funds Transfers
spellingShingle HG1710 Electronic Funds Transfers
Ching, Yen Choon
Fair E-Cash System for Internet Payment
description In a fair e-cash system, the trustee holds the ability to revoke the anonymity of a user. Anonymity revocation means tracing where a user has spent the coins ( coin tracing) or tracing whom a spent coin belongs to ( owner tracing ) . The trustee is expected to revoke the anonymity of a user only when instructed by the court. This allows the law enforcement authority to catch users who use the e-cash for criminal activities while protecting the anonymity of those that do not misuse it. A fair e-cash system is called off-line if the trustee is only involved during the revocation process. Previous schemes required the tracing information to be constructed for each coins. This resulted in high computation during withdrawal time and the coin size is quite large. Thus, it is not suitable to be implemented on devices with limited memory or processing capability such as smart cards, PDAs or WAP phones. In this thesis, we proposed a different approach to construct an off-line fair e-cash system which resulted in a significant reduction in terms of computation and storage. We use what we call a license to achieve tracing. This license will contain the user's information which the trustee can extract out for tracing purposes. There is no monetary value associated with this license. The user must always present a valid license for every transaction. Since the tracing information is not constructed into the coin, the coin will have a simpler 'structure'. We still require the user to include his identity in the coin. However, the user does not need to prove that this is correctly done during withdrawal time. He only needs to show that the identity embedded in the coin is the same as the identity embedded in the license during payment time. This is to prevent the coins from being used by someone else except the withdrawer. Using this new approach , the coins vannot be traced directly. Instead, one has to trace the licenses withdrawn. This indirectly allows the law enforcement authority to trace the whereabouts of suspicious withdrawal. For the owner tracing, the tracing is accomplished using the license. The design is simple and direct. This allows us to easily analyze the security of the scheme and also to reduce implementation errors.
format Thesis
qualification_level Master's degree
author Ching, Yen Choon
author_facet Ching, Yen Choon
author_sort Ching, Yen Choon
title Fair E-Cash System for Internet Payment
title_short Fair E-Cash System for Internet Payment
title_full Fair E-Cash System for Internet Payment
title_fullStr Fair E-Cash System for Internet Payment
title_full_unstemmed Fair E-Cash System for Internet Payment
title_sort fair e-cash system for internet payment
granting_institution Multimedia University
granting_department Research Library
publishDate 2001
_version_ 1747829066403151872