A Framework to Evaluate Security and Cost of Time Stamping Schemes

Masashi UNE  Tsutomu MATSUMOTO  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E85-A   No.1   pp.125-139
Publication Date: 2002/01/01
Online ISSN: 
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Cryptography and Information Security)
time stamp,  security evaluation,  cost evaluation,  

Full Text: PDF(626.5KB)>>
Buy this Article

Time stamping is a technique used to prove the existence of certain digital data prior to a specific point in time. With the recent expansion of electronic commerce, it has been widely recognized as an important technique for ensuring the integrity of digital data for a long time period. Recently, various time stamping schemes have been proposed. However, a framework for evaluating their security and cost has not yet been established. Therefore, it has been difficult for users and system designers to select appropriate time stamping schemes. This paper presents a new framework for evaluating the security and cost of time stamping schemes. Our framework classifies time stamping schemes into 108 categories and clarifies their characteristics with regard to security and cost. By applying our framework to a certain scheme, we can easily evaluate its security and cost without discussing details of its specification. In this paper, we explain the basic idea of our framework and show how to use it by applying it to four existing schemes: Digital Notary/SecureSeal, PKITS, TIMESEC and Cuculus.