Privacy-preserving publish-subscribe protocol in a cloud-assisted model

A computer-implemented method for providing privacy in a publish-subscribe protocol, comprising the steps of:

• receiving, by a third party from a server, at least one intermediate topic pseudonym for at least one topic associated with an item, at least one interest pseudonym for at least one interest associated with a client, and an encrypted item;
• applying, by the third party, a function using a server key to the at least one intermediate topic pseudonym to produce at least one topic pseudonym associated with the item;
• determining, by the third party, whether one of the at least one topic pseudonym is equal to one of the at least one interest pseudonym;
• and
• transmitting, by the third party, the encrypted item to the client when one of the at least one topic pseudonym is equal to one of the at least one interest pseudonym of the client.

A computer system, comprising:

• a memory;
• a processing device, coupled to the memory, the processing device to:
• receive, from a client, at least one interest pseudonym produced by the application of a function using a server key to at least one interest of the client to produce at least one intermediate interest pseudonym and the application the function using a third party key to the at least one intermediate interest pseudonym to produce the at least one interest pseudonym;
• encrypt an item;
• compute at least one intermediate topic pseudonym for at least one topic associated with the item by applying the function using the server key to each of the at least one topic associated with the item;
• and
• transmit the at least one intermediate topic pseudonym, the at least one interest pseudonym, and the encrypted item to a third party.