Cipher

What Is a Cipher?

A cipher is a cryptographic concept that arose as a solution to the need for secure communication. It enables individuals to exchange information in secrecy, preventing unauthorized parties from violating their privacy.

Ciphers play a fundamental role in cryptography. They function by converting the original message, known as plaintext, into encoded text called ciphertext. This ciphertext can be safely transmitted to the recipient. To decrypt the message and retrieve the original plaintext, the recipient must possess a specific piece of information referred to as a “key.”

Prior to initiating communication, the sender and recipient agree upon the key. A strong cipher should generate ciphertext that is extremely difficult or impossible to decrypt without knowledge of the key.

Classical ciphers, which relied on manual methods, have been replaced by more efficient computer-assisted encryption techniques. These earlier ciphers can be categorized into two main types: substitution ciphers and transposition ciphers.

However, advancements in cryptanalysis have made manual ciphers easily crackable and outdated. The emergence of electromechanical encryption devices, such as the Enigma machine, extended their usefulness until corresponding decryption devices, like the British bombe, were developed.

Modern cryptographic ciphers are computationally intensive, necessitating the use of computers for effective encryption. Even with the most powerful machines available, decryption is prohibitively expensive.

Cryptocurrencies heavily rely on cryptography, including ciphers, to ensure the continuous operation and high security of their networks.