Patent ID: 8214640

Claim:
A method for sending selected information from one Session Initiation Protocol (SIP) end-point agent to another SIP end-point agent, the method comprising: selecting the information to be sent; encrypting the information by a processor; selecting one or more header fields of an SIP message to be sent from the SIP end-point agent, the selected header fields each having a first portion defined according to the SIP protocol as representing a transactional characteristic of the header field and a second portion representing identification information specific to the SIP message; embedding, by a processor, the encrypted information in the second portion of the one or more selected SIP header fields; prepending, by a processor, the encrypted information with a user-defined initial search string previously exchanged between the SIP end-point agents, wherein the user-defined initial search string indicates the presence of the encrypted information to be recovered from the second portion of the one or more selected SIP header fields, and wherein an initial character of the user-defined initial search string indexes a parameter-value pair format, command format or message format of the encrypted information to which the user-defined initial search string is prepended; and transmitting the SIP message that includes said selected field or fields, wherein the encrypted information embedded in the second portion of the one or more selected fields will not be read for information content by intermediate SIP agents in the transmission path between the SIP end-point agents.