The Role of Cryptographic Scrambler Functions in Security with a Passive Defense Approach

Information and communications security is of utmost importance in both military and security fields. Establishing an appropriate and improved cover to safeguard security and authenticity in communications and information matters through cryptography and communication protocols is possible. The mechanisms which contribute to the security of the transmission and reception of a message are related to passive defense and will contribute to the reduction of information vulnerability. On the other hand, the communication protocols which review the authenticity of a piece of communication or information, cause the reduction of access of unauthorized personnel to confidential information and, moreover, will reduce the vulnerability of a communication network through processes such as lack of saving huge files, lack of access to parts of a message, creating the message summary with a very short length for each long secret and non-secret message and so on. The above process is a very precise concept of passive defense, because it will dramatically reduce the communication and information vulnerability in communication protocols. The security of a message through cryptography is obtainable. In many cases, the aim of the sender and the receiver of a message is the authenticity and integrity of the message. This is made possibly through the use of communication protocols such as digital signatures, scrambler functions, message credit codes and so on.The scrambler functions play a fundamental role in the communication protocols. For instance, failing to use a scrambler function in a digital signature will cause the dysfunction of the signature. In this essay, the exact concept of security and the applications of scrambler functions will be expressed and then the course of the development of these functions will be mentioned, as well.One of the new functions, called Grostal (one of the five scrambler functions which has reached the third stage of the NIST contest and the one that we think will eventually be selected by this institute as a global scrambler function) will be reviewed in terms of structure and as a new task, the security of this function against cubic attacks will also be analyzed.