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Data Encryption Algorithm
An ANSI Standard that describes a cryptographic algorithm for encrypting data. The algorithm is private key driven. Also referred to as the Data Encryption Standard (DES)

Data Encryption Standard
See Data Encryption Algorithm

Data Integrity
The formal definition of comprehensive rules and the consistent application of those rules to assure high integrity data. It consists of techniques to determine how well data are maintained in the data resource and to ensure that the data resource contains data that have high integrity. Data integrity includes techniques for data value integrity, data structure integrity, data retention integrity, and data derivation integrity.

Deception
Giving fake or forged identity or authentication to break the security policy.

Decryption
Decryption is the process of transforming ciphertext back into plaintext. It is the reverse of encryption

Designated Approving Authority (DAA)
An example would be the secure server administrator having the authority to make a decision on accepting the security safeguards that are prescribed for an ais or the administrator who might be responsible for issuing an accreditation statement which records the pronouncement to accept those safeguards.

Digest
A data piece of specific length, measured from a file or message. More often that not digest is a part of a digital signature and is known as hash or message digest.

Digital Signature
A digital signature (not to be confused with a digital certificate) is an electronic rather than a written signature. It can be used with any kind of message, whether it is encrypted or not, simply so that the receiver can be sure of the sender's identity and that the message arrived intact. A digital certificate contains the digital signature of the certificate-issuing authority so that anyone can verify that the certificate is real. Additional benefits to the use of a digital signature are that it is easily transportable, cannot be easily repudiated, cannot be imitated by someone else, and can be automatically time-stamped.

Digital Signature Algorithm (DSA)
An algorithm for producing digital signatures, developed by NIST and the NSA. To sign a message, Alice uses the DSA Sign Algorithm to encode a digest of the message using her private key. For all practical purposes, there is no way to decrypt this information. However, anyone who receives the message and accompanying digital signature can verify the signature by using the DSA Verify Algorithm to process the following information: the received signature; a digest of the received message; and Alices public key. If the output of this algorithm matches a certain part of the digital signature, the signature is valid and the message has not changed. In contrast to RSA and other encryption-based signature algorithms, DSA has no ability to encrypt or decrypt information.

Digital Signature Standard (DSS)
A National Institute of Standards and Technology (NIST) standard for digital signatures, used to authenticate both a message and the signer. DSS has a security level comparable to RSA (Rivest-Shamir-Adleman) cryptography, having 1,024-bit keys.