Authenticated Broadcast With a Partially Compromised Public-Key Infrastructure
Source: University of Maryland
Given a Public-Key Infrastructure (PKI) and digital signatures, it is possible to construct broadcast protocols tolerating any number of corrupted parties. Almost all existing protocols, however, do not distinguish between corrupted parties (Who do not follow the protocol), and honest parties whose secret (Signing) keys have been compromised (But who continue to behave honestly). This paper explores conditions under which it is possible to construct broadcast protocols that still provide the usual guarantees (i.e., Validity/agreement) to the latter.