Method and apparatus for ensuring privacy in communications between parties

摘要

A method of improving privacy by hiding, in an ordered sequence of messages M[x(1), D(1)], M[x(2), D(2)], etc, communicated between a first and at least one second party sharing a key k, metadata x(i) descriptive of message processing, wherein D(i) denotes payload data. The method comprises the first and the second party agreeing on a pseudo random mapping depending on a shared key k, Fk, mapping at least x(i) to y(i), and the first party modifying the messages by replacing x(i) by y(i) in each message M(x(i), D(i)). The first party then transmits the modified messages maintaining their original order, and on reception of a message M(y(m), D), the second party uses a mapping Gk to retrieve position m of received value and the original value x(m).

主权项

1. A method of ensuring privacy in communications between a first party and one or more second parties over a communications network, the method comprising:
making same pseudo-random sequence of values available to each of the first and second parties, and maintaining a mapping between the pseudo-random sequence of values and values which is used by a party receiving a message sent by the first party to handle the message or its contents; in messages to be sent between the first party and the second party, using a value from the pseudo-random sequence in place of the value to which the value from the pseudo-random sequence is mapped; at the receiving party, identifying the replaced value on the basis of the substituted value, and handling the message accordingly; and changing the value used from the pseudo-random sequence from message to message or periodically, wherein the first and second parties are end parties of the messages, and wherein the value is used as an identifier of the first party or is further processed to generate the identifier.