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87 Cards in this Set
- Front
- Back
The science that involves the use of codes and cyphers to obscure the meaning of a message.
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Cryptology
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The science of protecting data so that it may be stored and transmitted between parties while preserving confidentiality and/or integrity.
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Cryptography
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The science of breaking cryptographic algorithms to obtain the secret message without authorization.
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Cryptanalysis
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Sets of techniques that implement cryptography.
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Cryptosystems
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The mathematical function used to encrypt and decrypt messages.
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Algorithm
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The binary sequence used to provide secrecy to the algorithm.
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Key
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The original message in an unencrypted readable form.
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Plaintext
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The encrypted version of the message, unreadable without the correct algorithm and key.
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Ciphertext
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The practice of transforming plaintext into ciphertext with an algorithm and key.
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Encryption
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The practice of transforming ciphertext into plaintext with an algorithm and key.
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Decryption
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Symbols or words used to represent other words or phrases.
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Codes
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Mathematical functions to transform bits or characters into other bits or characters.
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Ciphers
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Two types of ciphers.
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Block, stream
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Ciphers that work on plaintext and ciphertext in chunks of a discrete size.
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Block
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Chipers that work on plaintext and ciphertext in a bitwise or characterwise fashion.
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Stream
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Random numbers used to introduce unpredictability into a cryptosystem.
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Nonces
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Logical function that is true only when both arguments are true.
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AND
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Logical function that is true when one or both of the arguments are true,
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OR
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Logical function that is true only when one or both elements are false.
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NAND (not AND)
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Logical function that is true only when both elements are false.
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NOR (not OR)
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Logical function that is true only when a single argument is false.
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NOT
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Logical function that is true only when one of the elements is true and the other is false.
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XOR (exclusive OR)
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Function that is equal to the remainder after performing integer division.
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Modulo
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A mathematical function that is easy to compute but practically impossible to compute the inverse operation.
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One way function
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A historical cipher that is generated by shifting each character three places to the right.
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Caesar cipher
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Ciphers that use multiple alphabets on a rotating basis.
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Polyalphabetic substitution
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Ciphers that move the letters of a message around in a manner that obscures their meaning.
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Transformation
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Ciphers that make use of a one time pad that uses a new key for each message, preventing most cryptanalysis techniques.
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Vernam
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Ciphers that use an extremely long key, usually drawn from a source such as a book.
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Running
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Two parties communicate with each other using the same secret key to encrypt and decrypt messages.
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Secret key cryptography.
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Once the only federally approved symmetric cryptosystem.
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DES
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Four modes of DES encryption.
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ECB, CBC, CFB, OFB
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DES modes that allow errors to propagate.
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CBC, CFB
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DES modes that do not allow errors to propagate.
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ECB, OFB
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Encryption that uses DES to encrypt the same message using two or three different keys.
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Triple DES (3DES)
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Key length of DES.
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56 bits
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Block size of DES
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64 bit
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Key length of 3DES.
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168 bits
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Four modes of 3DES.
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DES-EEE3, DES-EDE3, DES-EEE2, DES-EDE2
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3DES method using three different keys in encrypt mode.
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DES-EEE3
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3DES mode using three different keys, two in encrypt mode and one in decrypt mode.
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DES-EDE3
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3DES mode using two different keys to perform three encryption operations.
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DES-EEE2
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3DES mode using two different keys to perform two encryption operations and one decrypt operation.
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DES-EDE2
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Cipher used by AES.
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Rijndael block cypher
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AES key lengths.
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128, 192, 256
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AES block length.
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128 bits
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Effective block length of 3DES when using two keys.
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112 bits
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Effective block length of 3DES when using three keys.
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168 bits
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Symmetric algorithms.
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DES, 3DES, CAST, SAFER, Skipjack, Blowfish, Twofish, RC*, IDEA
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Blowfish key length.
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32 to 448 bits
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Twofish key length.
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256 bits
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Twofish block length
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128 bits
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RC5 key length.
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up to 2048 bits
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RC5 block length.
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32, 64, or 128 bits
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IDEA key length.
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128 bits
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IDEA block length.
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64 bits
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The use of image manipulation techniques to hide information in messages.
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Steganography
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Asymmetric algorithms.
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RSA, El gamal, Merkle-hellman knapsack, Elliptic curve, diffie-hellman, LUC
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Using asymmetric algorithms to certify the integrity of a message while in transit and ensure nonrepudiation.
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Digital signature.
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Hash that produces a 128 bit digest.
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MD5
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Hash that produces a 160 bit digest.
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SHA-1
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Hash that produces a 256 bit digest.
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SHA-256
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Hash that produces a 512 bit digest.
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SHA-512
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The most common form of encrypted email.
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Secure multipurpose internet mail extensions (S/MIME)
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Competitor for S/MIME that is not as commonly used.
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MIME object security standard (MOSS)
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Mail encryption that uses 3DES, RSA, MD5, and X.509.
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Privacy enhanced mail (PEM)
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Mail encryption that uses a web of trust to allow users to vouch for each others keys.
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Pretty good privacy (PGP)
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A standard proposed by netscape and commonly used to secure communications over the web and other internet protocols.
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Secure sockets layer (SSL)
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A standard proposed by credit card issuers but never became widely adopted.
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Secure electronic transaction (SET)
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A follow on protocol to SSL used to secure application level protocols.
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Transport layer security (TLS)
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Solves the problem of distributing authenticated public keys among users of asymmetric cryptosystems.
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Public key infrastructure (PKI)
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Certificates that PKI is based on.
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X.509 v3
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Guesses a cryptographic key by exhaustively checking all of the possibilities.
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Brute force
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Looks for weaknesses in the cryptopgraphic algorithm itself or in a particular software or hardware implementation.
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Vulnerability exploit
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Uses a mathematical analysis of a message to break the cryptosystem.
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Statistical
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Begins with an attacker having knowledge of a plaintext message and the corresponding ciphertext.
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Known plaintext
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Occurs when the attacker is able to determine the ciphertext that corresponds to a plaintext message of their choosing.
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Chosen plaintext
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Occurs when the attacker is able to determine the plaintext message that corresponds to a ciphertext of their choosing
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Chosen ciphertext
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Occurs when the attacker is able to find two plaintext messages that generate the same ciphertext,
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Birthday attack
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Occurs when an attacker has the plaintext and ciphertext and is able to use both simultaneously to determine the secret key
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Meet in the middle attack
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Occurs when the attacker is able to trick both communicating parties into thinking that they are communicating with each other when they are both actually communicating with the attacker who is relaying messages.
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Man in the middle attack
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Occurs when an attacker is able to obtain the ciphertext and later use it to impersonate the transmitter by simply using the same ciphertext even though they may not know the corresponding plaintext
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Replay
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Substitution cipher that uses a different alphabet for each letter of the plaintext message.
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One time pad
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Generates a unique message output value derived from the content of a message.
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Message digest
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A mechanism to prove knowledge of a fact to a third party without revealing the fact itself to that third party.
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Zero knowledge proof
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Protects entire communication circuits by creating a secure tunnel between two points.
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Link encryption
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Protections communications between two parties and is performed independently of link encryption.
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End to end encryption
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