Public key cryptosystems (also called asymmetric cryptosystems) are characterized by using different keys for encryption and decryption of information. Its main advantage is that they facilitate the process of distribution and exchange of keys among the participants of secure communication, which was a major problem of symmetric or private key cryptosystems. Asymmetric algorithms generally employ … Read more Public Key Encryption

RSA cryptosystem Among all asymmetric algorithms, RSA is the most used and also perhaps the easiest to understand and implement. A peculiarity of this algorithm is that its two keys serve both to encrypt and to authenticate. It owes its name to its three inventors: Ronald Rivest, Adi Shamir and Leonard Adleman, who first published … Read more RSA

Vigenère cipher It is a typical example of polyalphabetic encryption whose invention was wrongly attributed to Blaise de Vigenère, and dating back to the 16th century. The key consists of a sequence of symbols of the alphabet K = {k0, k1, …, kd-1}, of length d, and which uses the following linear congruent transformation of … Read more Vigenére Cipher

Monoalphabet substitution encryption A monoalphabet substitution such as César encryption can be expressed by a congruent linear transformation (also known cryptographically as a related transformation). In César encryption, this would be written as E (M) = (M + 3) mod N, where N is the length or cardinal of the original alphabet. The transformation related … Read more Substitution Cipher

Caesar cipher encryption is one of the first historically known encryption methods. Julio César used it to send orders to his generals on the battlefields. It consisted of writing the message with an alphabet that was formed by the letters of the normal Latin alphabet displaced three positions to the right. With our alphabet the … Read more Caesar cipher encryption

What is cryptography The word Cryptography comes from the Greek “kryptos” which means hidden, and “graphia”, which means writing, and its definition according to the dictionary is “Art of writing with a secret key or in an enigmatic way”. Cryptography is a technique, or rather a set of techniques, that originally deal with the protection … Read more Cryptography Definition