System and method for efficient and semantically secure symmetric encryption over channels with limited bandwidth

摘要: One embodiment of the present invention provides a system for enhancing security in secure communication channel. During operation, collects contextual information associated with mobile device or user and determines whether trigger condition is met based on collected information. In response to determining that met, performs first type key-ratcheting operation current cryptographic key update key. not second The then encrypts to-be-sent message using an encryption updated