It can ensure integrity of communications. It can increase assurance that received messages are genuine. Because cryptography for confidentiality purposes has the potential to interfere with foreign intelligence gathering, it is often subject to stringent export controls. Integrity is a security service that permits a user to detect whether information has been tampered with during transmission or while in storage. Closely related to integrity is authenticity, which provides a user with a means of verifying the identity of the sender of a message.
Authentication frequently involves associating a unique cryptographic key with a user.
Integrity and authenticity services are often implemented in tandem. Cryptography that provides integrity and authenticity only does not interfere with many types of intelligence gathering. Weak Links Electronic communication networks are complex systems built out of many components. An intruder wishing to access the communications in a network will look for unprotected points or segments. The weakest link is where one might be able to bypass or avoid the security mechanisms altogether.