Hiding messages from potential enemies
The act of taking a message, called plaintext and applying an operation to it, called a cipher, so that you receive a garbled, unreadable message as the output, called ciphertext
The underlying logic of process that’s used to convert the plaintext into ciphertext
if no one knows what algorithm we’re using, we’re safe from attackers.
A collection of algorithms for key generation and encryption and decryption operations that comprise a cryptographic service should remain secure - even if everything about the system is known, except the key
The system should remain secure even if your adversary knows exactly what kind of encryption systems you’re employing, as long as your keys remain secure.
Overarching discipline that convers the practice of coding and hiding messages from third parties
The study of this practice is referred to as cryptology.
The opposite of this, looking for hidden messages or trying to decipher coded message is referred to as cryptanalysis.
The practice of studying the frequency with which letters appear in a ciphertext