Improving Robustness of PGP Keyrings by Conflict Detection

Secure authentication frequently depends on the correct recognition of a user’s public key. When there is no certificate authority, this key is obtained from other users using a web of trust. If users can be malicious, trusting the key information they provide is risky. Previous work has suggested the use of redundancy to improve the trustworthiness of user-provided key information. In this paper, we address two issues not previously considered. First, we solve the problem of users who claim multiple, false identities, or who possess multiple keys. Secondly, we show that conflicting certificate information can be exploited to improve trustworthiness. Our methods are demonstrated on both real and synthetic PGP keyrings, and their performance is discussed.

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