Abstract: A method for distributed delegation and verification includes: a service provider generating first delegation information including authorization credentials and self-signed credentials thereof to establish a delegation relationship with a first service node; the first service node generating second delegation information including the authorization credentials in the first delegation information and self-signed credentials thereof to establish a delegation relationship with a service requestor; upon receipt from the service requestor of a service request including the delegation information issued to the service requestor, the service provider requesting the first service node to verify the self-signed credentials in the delegation information in the service request; the first service node performing verification; and upon successful verification by the first service node, the service provider verifying the authorization credentials in the delegation information in the service request and, upon successful ve

Abstract: In a method and system for providing Internet Key Exchange (IKE) during a Session Initiation Protocol (SIP) signaling session, the method includes: enabling a caller end node device to send a first SIP request message to a callee end node device, wherein the first SIP request message includes a payload unit of a first IKE quick mode initial message; enabling the callee end node device to respond to the first SIP request message with an SIP response message, wherein the SIP response message including includes a payload unit of an IKE quick mode response message; and enabling the caller end node device to send a second SIP request message to the callee end node device, wherein the second SIP request message includes a payload of a second IKE quick mode initial message.