Patent ID: 8204228

Claim:
A computer-implemented method comprising: at a key server: receiving a registration request from a network element to join a group of network elements managed by the key server; generating and storing a group member registration state comprising information identifying the network element belonging to the group of network elements; generating a token using information from the group member registration state, wherein the token identifies the network element belonging to the group of network elements; deleting the group member registration state for the network element at the key server; generating an encrypted token by encrypting the token using a secret key that is local to the key server; sending the encrypted token to the network element; receiving a re-registration request from the network element to rejoin the group of network elements, wherein the re-registration request comprises the encrypted token; generating a decrypted token by decrypting the encrypted token using the secret key; using data from the decrypted token, recovering and storing the group member registration state, comprising information identifying the network element belonging to the group of network elements; and re-registering the network element using the information from the group member registration state.