Study and Comparison of Different Crypto systems interms of DATA Confidentiality

Encryption is the study of techniques used to keep data confidential. When personal, financial, military, or national security information is sent around, it becomes subject to interception tactics. Such problems can be avoided by encrypting the information and making it inaccessible to unwanted (third parties). Logs are created by people trying to create a system that prevents third parties from inserting or impersonating communications into their communications.. In this paper the following cryptographic protocols, will be presented: Wide-Mouth Frog, Yahalom, Needham-Scroeder, Otway-Rees, Kerberos, Neuman-Stubblebine, Denning-Sacco and Woo-Lam. Firstly, we will present each protocol shortly with its most important properties, followed by their comparative analysis. We will also make analysis of the the attacks they are resistant to, as well as the attacks that make them vulnerable and they are subject to. The main problem these protocols are working on is the safe exchange of secret keys between the two parties, and ensuring them that the communication is with the person they want, rather than with a stranger. Codes and protocols are important tools, but they are a poor substitute for the real, critical thinking about what is really protected and how different methods of defense may fall. Even if the intruder has access only to the ciphertext, such small cracks in some parts of the system could provide sufficient information, thus turning good cryptosystems into useless.