Glossary of Terms (page 1)
adaptive-chosen-ciphertext - A version of the chosen-ciphertext attack where the cryptanalyst can choose ciphertexts dynamically.
A Cryptanalyst can mount an attack of this type in a scenario in which he or she has free use of a piece of decryption hardware, but is unable to extract the decryption key from it.
adaptive-chosen-plaintext - A special case of the chosen-plaintext
attack in which the cryptanalyst is able to choose plaintexts dynamically, and alter his or her choices base on the results
of previous encryptions.
adversary - Commonly used to refer to the opponent, the enemy, or
any other mischievous person that desires to compromise one's security.
AES - The Advanced Encryption Standard that will replace DES
(The Data Encryption Standard) around the turn of the century.
algebraic attack - A method of cryptanalytic attack used against
block ciphers that exhibit a significant amount of mathematical structure.
algorithm - A series of steps used to complete a task.
Alice - The name traditionally used for the first user of
cryptography in a system: Bob's friend.
ANSI - American National Standards Institute.
API - Application Programming Interface.
attack - Either a successful or unsuccessful attempt at breaking
part or all of a cryptosystem. See algebraic attack, birthday attack, brute force attack, chosen ciphertext attack, chosen
plaintext attack, differential cryptanalysis, known plaintext attack, linear cryptanalysis, middleperson attack.
authentication - The action of verifying information such as
identity, ownership or authorization.
biometrics - The science of using biological properties to
identify individuals; for example, fingerprints, retina scan and voice recognition.
birthday attack - A brute-force attack used to find collisions.
It gets its name from the surprising result that the probability of two or more people in a group of 23 sharing the same
birthday is greater than 1/2.
bit - A binary digit, either 1 or 0.
blind signature scheme - Allows one party to have a second party
sign a message without revealing any (or very little) information about the message to the second party.
block - A sequence of bits of fixed length; longer sequences of
bits can be broken down into blocks.
block cipher - A symmetric cipher which encrypts a message by
breaking it down into blocks and encrypting each block.
block cipher based MAC - MAC that is preformed by using a block
cipher as a keyed compression function.
Bob - The name traditionally used for the second user of cryptography
in a system; Alice's friend.
boolean expression - A mathematical expression in which all variables
involved are either 0 or 1; it evaluates to either 0 or 1.
brute force attack - This attack requires trying all (or a large
fraction of all) possible values till the right value is found; also called an exhaustive search.