A Survey on Different Techniques for Message Security and Authentication in Offline Chatting?

In today’s world scenario, data security plays an important role where importance is given to authentication, confidentiality, integrity and non repudiation. The universal technique to providing confidentiality of transmitted data is cryptography. Here we use group key management (GKM) in mobile communication where it is important to enable access control for a group of users. In GKM, a major issue is how to minimize the communication cost for group rekeying. While designing the optimal GKM, researchers have assumed that all group members have the same leaving probabilities and that the tree is balanced and complete to simplify analysis. These assumptions are impractical and may lead to a large gap between the impractical analysis and the measurement in real-life situations, thus allowing for GKM schemes to incorporate only a specific number of users. A new GKM framework supporting more general cases that do not require these assumptions. In which Armstrong number is used for cryptography process. In authentication process color is important which acts as password.