Patent ID: 9660813
Date: 2017-05-23
CPC Classifications: G06F,H04L

Claim:
1. A method comprising the steps of: mapping a group of clients into a plurality of subgroups of bounded size; communicating to a given one of the clients information identifying the particular subgroup to which that client belongs as well as the other clients in that subgroup; and receiving a ring signature from the given client that is generated over the corresponding subgroup of clients based on the communicated information; wherein the size of a given subgroup is dynamically determined based on a current value of a variable privacy parameter; wherein the given subgroup of clients comprises a subgroup of u+1 clients randomly selected from a group of n clients, where u and n are integers greater than zero; wherein the subgroup of u+1 clients is randomly selected from the group of n clients by computing hash values h(m∥k), where m denotes a message, and where k is the smallest integer for which h(m∥k) interpreted as u+1 sequences of log n bits represents u+1 distinct clients including the given client; wherein public keys of the u+1 clients are utilized to verify the ring signature; wherein the steps are performed by a server that communicates with the clients over a network; and wherein each of the server and the clients is implemented as at least one processing device comprising a processor coupled to a memory.