Identity-based cryptography: Difference between revisions

Revision as of 14:59, 22 August 2023

Revision as of 06:14, 16 September 2023

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==Limitation==

Identity-based systems have a characteristic problem in operation. Suppose Alice and Bob are users of such a system. Since the information needed to find Alice's public key is completely determined by Alice's ID and the master public key, it is not possible to revoke Alice's credentials and issue new credentials without either (a) changing Alice's ID (usually a phone number or an email address which will appear in a corporate directory); or (b) changing the master public key and re-issuing private keys to all users, including Bob.<ref name=green1>{{Cite book |archive-url=https://archive.phtoday/20210608113615/https://ieeexplore.ieee.org/document/7163033 |doi=10.1109/SP.2015.26 |archive-date=8 June 2021 |publication-date=20 July 2015 |date=17 May 2015 |chapter-url=https://ieeexplore.ieee.org/document/7163033 |publisher=ACM |last1=Green |first1=Matthew |last2=Miers |first2=Ian |title=2015 IEEE Symposium on Security and Privacy |chapter=Forward Secure Asynchronous Messaging from Puncturable Encryption |pages=305–320 |isbn=978-1-4673-6949-7 |s2cid=9171925 |access-date=8 June 2021 |url-status=live }}</ref>

This limitation may be overcome by including a time component (e.g. the current month) in the identity.{{r|green1}}