Test 3 NEED

session keys

Limited-use symmetric keys for temporary communications during an online session.

plaintext or cleartext

The original unencrypted message, or a message that as been successfully decrypted.

Secure electronic transactions (SET)

a protocol developed by credit card companies to protect against electronic payment fraud

message digest

a value representing the application of a hash algorithm on a message that is transmitted with the message so it can be compared with the recipient's locally calculated hash of the same message. If both hashes are identical after transmission, the message has arrived without modification. Also known as a hash value.

Diffie-Hellman key exchange

A hybrid cryptosystem that facilitates exchanging private keys using public-key encryption.

Secure Sockets Layer (SSL)

A security protocol developed by Netscape to use public-key encryption to secure a channel over the internet.

Privacy Enhanced Mail (PEM)

A standard proposed by the Internet Engineering Task Force (IETF) that uses 3DES symmetric key encryption and RSA for key exchanges and digital signatures.

Template cipher

is not strictly an encryption cipher, but more of an example of stegonography.

Steganography

the process of hiding messages; for example, hiding a message within the digital encoding of a picture or graphic so that it is almost impossible to detect that the hidden message even exists.

steganography

the process of hiding messages; for example, hiding a message within the digital encoding of a picture or graphic so that it is almost impossible to detect that the hidden message even exists.

cryptography

the process of making and using codes to secure information

cryptanalysis

the process of obtaining the plain text message from a ciphertext message without knowing the keys used to perform the encryption

Block Cipher

An encryption method that involves dividing the plaintext into blocks or sets of bits and then converting the plaintext to ciphertext one block at a time.

Public Key Infrastructure (PKI)

An integrated system of software, encryption methodologies, protocols, legal agreements, and third-party services that enables users to communicate securely through the use of digital certificates.

Registration Authority (RA)

In PKI, a third party that operates under the trusted collaboration of the certificate authority and handles day-to-day certification functions.

digital certificates

Public-key container files that allow PKI system components and end users to validate a public key and identify its owner.

nonrepudiation

The process of reversing public-key encryption to verify that a message was sent by the sender and thus cannot be refuted.

ciphertext or cryptogram:

The unintelligible encrypted or encoded message resulting from an encryption.

WPA

Wifi protected access, has a key size of 128 bits. It uses dynamic keys created and shared by an authentication server.

WEP

Wired Equivalent Privacy, an encryption algorithm used to protect data on Wi-Fi Networks, used RC4 cipher stream to encrypt each packet using a 64-bit key.

WPA2

better WPA with AES based encryption

digital signatures

encrypted message components that can be mathematically proven as authentic

Message Authentication Code (MAC)

A key-dependent, one-way hash function that allows only specific recipients (symmetric key holders) to access the message digest.

Encapsulating Security Payload (ESP)

In IPSec, a protocol that provides secrecy fo the contents of network communications as well as system-to-system authentication and data integrity verification

transport mode

In IPSec, an encryption method in which only a packet's IP data is encrypted, not the IP headers themselves; this method allows intermediate nodes to read the source and destination addresses.

tunnel mode

In IPSec, an encryption method in which the entire IP packet is encrypted and inserted as the payload in another IP packet. This requires other systems at the beginning and end of the tunnel to act as proxies to send and receive the encrypted packets and then transmit the packets to their ultimate destination.

Certificate Revocation List (CRL)

In PKI, a published list of revoked or terminated digital certificates.

Digital Signature Standard (DSS)

The NIST standard for digital signature algorithm usage by federal information systems. DSS is based on a variant of the EIGamal signature scheme.

IP Security (IPsec)

The primary and now dominant cryptographic authentication and encryption product of the IETF's IP Protocol Security Working Group. A framework for security development within the TCP/IP family of protocol standards, IPSec provides application support for all uses within TCP/IP, including virtual private networks.

asymmetric encryption

a crypographic method that incorporates mathematical operations involving both a public key and a private key to encipher or decipher a message. Either key can be used to encrypt a message, bu the other key is required to decrypt it.

symmetric encryption

a cryptographic method in which the same algorithm and secret key are used both to encipher and decipher the message

permutation cipher/transposition cipher

a cryptographic operation that involves simply rearranging the values within a block based on an established pattern.

vernam cipher

a cryptographic technique developed at AT&T and known as the "one-time pad," this cypher uses a set of characters for encryption operations and only one time and then discards it.

exclusive OR operation (OXR)

a function within Boolean algebra used as an encryption function in which two bits are compared. If the two bits are identical, the result is binary 0, otherwise , the result is a binary 1.

secret key

a key that can be used in symmetric encryption both to encipher and decipher the message

Secure Multipurpose Internet Mail Extensions (S/MIME)

a security protocol that builds on the encoding format of the Multipurpose internet Mail Extensions(MIME) protocol and uses digital signatures based on public key cryptosystems to secure e-mail.

link encryption

a series of encryption and decryption between a number of systems, wherein each system in a network decrypts the message sent to it and then reencrypts the message using different keys and sends it to the next neighbor. This process continues until the message reaches the final destination.

Secure Hash Standard (SHS)

a standard issued by the National Institute of Standards and Technology (NIST) that specifies secure algorithms, such as SHA-1, for computing a condensed representation of a message or data file.

Polyalphabetic substitution

a substitution cipher that incorporates two or more alphabets in the encryption process

monoalphabetic substitution

a substitution cipher that only incorporates a single alphabet in the encryption process

vigenere cipher

an advanced type of substitution cipher that uses a simple polyalphabetic code

substitution cipher

an encryption method in which one value is substituted for another

Bit stream cipher

an encryption method that involves converting plaintext into blocks or sets of bits and then converting the plaintext to ciphertext one block at a time

Secure HTTP (S-HTTP)

an extended version of Hypertext Transfer Protocol that provides for the encryption of protected Web pages transmitted via the Internet between a client and server

application header (AH) protocol

in IPSec, a protocol that provides system-to-system authentication and data integrity verification, but does not provide secrecy for the content of a network communication

Certificate Authority (CA)

in PKI, a third party that manages users' digital certificates.

Book Cipher

in a book cipher the ciphertext consists of a list of codes representing the page number , line number, and word number of the plaintext word.

hash functions

mathematical algorithms that generate a message summary or digest (sometimes called a fingerprint) to confirm message identity and integrity

hash algorithms

public functions that create a hash value, also known as a message digest, by converting variable-length messages into a single fixed-length value

work factor

the amount of effort( usually expressed in units of time) required to perform cryptanaliysis on an encoded message

advanced encryption standard (AES)

the current federal standard for the encryption of data, as specified by NIST. AES is based on the Rijndael algorithm, which was developed by Vincent Rijmen and Joan Daemen

Keyspace

the entire range of values that can be used to construct an individual key

cryptology

the field of science that encompasses cryptography and cryptanalysis.

Key or cryptovariable:

the information used in conjunction with the algorithm to create the ciphertext from the plaintext; it can be a series of bits used in a mathematical algorithm or the knowledge of how to manipulate the plaintext. Sometimes called a cryptovariable.

algorithm

the mathematical formula or method use to convert an unencrypted message into an encrypted message. This is sometimes refers to the programs that enable the cryptographic processes

decryption

the process of converting an encoded or enciphered message (ciphertext) back to its original readable form(plaintext). Also referred to as deciphering.

encryption

the process of converting an original message (plaintext) into a form that cannot be used by unathorisized individuals (ciphertext). Also referred to as enciphering.

code

the process of converting components( words or phases) of an unencrypted message into encrypted components.

Running key cipher

the sender provides an encrypted message with a short sequence of numbers that indicate that the page, line and word number from a predetermined book to be used as a key or indicator block.

cipher

when used as a verb, the transformation of the individual components(characters, bytes, or bits) of an unencrypted message into encrypted components or vice versa( see decipher and encipher); when used as a noun, the process of encryption or the algorithm used in encryption, and a term synonymous with cryptosystem.