Patent ID: 8767965

Claim:
A method for a signature key infrastructure enabling detection of one or more parties responsible for repeated malicious activities in secure and anonymous communication among a plurality of parties, the method comprising steps of: generating a pool of keys using a key-generation algorithm; distributing to and associating with each party of the plurality of parties a small number of keys chosen randomly from the pool of keys; revoking a key of the chosen keys when the key is detected as used in a malicious activity, and creating a first set of parties associated with the revoked key; revoking additional keys that are randomly chosen among the keys of the pool that are not currently revoked, and selecting new keys randomly and independently generated using the key-generation algorithm; and when a party requests an updated key, sending the updated key selected from among the new keys to the requesting party, wherein if an other malicious activity is detected, creating a second set of the parties associated with a malicious activity key of the other malicious activity and identifying the parties in both the first set and the second set, the step of identifying comprising making an intersection set comprising the parties in both the first set and the second set.