Cryptography is the science of converting data into a secret code to hide the meaning of the message during transmission. Cryptographic systems provide the following security services:
- Confidentiality, by ensuring that only authorized parties can access data.
- Integrity, by verifying that data has not been altered in transit.
- Authentication, by proving the identity of the sender or receiver.
- Non-repudiation, by validating that communications have come from a particular sender at a particular time.
The following terms are related to cryptography:
|Plaintext||Plaintext is a readable message.|
|Cipher text||Cipher text is the message in a form that makes it unreadable to all but those for whom the message was intended.|
|Cryptographer||A cryptographer is a person who develops ways of converting plaintext to cipher text.|
|Cryptanalysis||Cryptanalys is is the method of recovering original data that has been encrypted without having access to the key used in the encryption process. This can be done to measure and validate the strength of a cryptosystem. It can also be done to violate the confidentiality and/or integrity of a cryptosystem.|
|Cryptosystem||A cryptosystem is the associated items of cryptography that are used as a unit to provide a single means of encryption and decryption.|
|Cryptology||Cryptology is the study of cryptography and cryptanalysis.|
|Key||A key is a variable in a cipher used to encrypt or decrypt a message. The key should be kept secret.
The key space is the range of the possible values that can be used to construct a key. Generally speaking, the longer the key space, the stronger the cryptosystem.
|Algorithm||A cipher or algorithm is the process or formula used to convert a message or otherwise hide its meaning. Examples of algorithms include:
|Encryption||Encryption is the process of using an algorithm to transform data from plaintext to a cipher text in order to protect the confidentiality, integrity, and sometimes the authenticity of the message.|
|Decryption||Decryption is the procedure used to convert data from cipher text into plaintext.|
|Steganography||Steganography, literally meaning "concealed writing", hides data or a message such that only the sender or the recipient suspects that the hidden data exists. Examples of steganography include:
|Quantum cryptography||Quantum cryptography uses a series of photons to encrypt and send messages. If the receiver knows the sequence and polarity of the photons, the message can be decoded.