ABSTRACT
In this chapter we present a description and a comparison of different methods of cryptography: symmetric cryptography, asymmetric cryptography, digital signature, and digital certificate. The comparative study of these methods helped us decide to use the method based on asymmetric cryptography using the algorithm Rivest-Shamir-Adleman (RSA) (Stallings 1999). This method has a mode of transmission faster than other algorithms that can be used (MD4, MD5, SHA, and SHA-1).
