Exam 20: Symmetric Encryption and Message Confidentiality

For general-purpose block-oriented transmission you would typically use _______ mode.

The National Bureau of Standards is now the National Institute of Standards and Technology.

For symmetric encryption to work the two parties to an exchange must share the same _____,which must be protected from access by others.

One disadvantage of the link encryption approach is that the message must be decrypted each time it enters a frame switch.

The most widely used encryption scheme is based on the _________ adopted in 1977 by the National Bureau of Standards.

Symmetric encryption is also referred to as secret-key or single-key encryption.

For general-purpose stream-oriented transmission you would typically use _______ mode.

"The plaintext is 64 bits in length and the key is 56 bits in length; longer plaintext amounts are processed in 64-bit blocks" is a description of the DES algorithm.

The three most important symmetric block ciphers are: 3DES,AES,and _____.

A ________ is a key used between entities for the purpose of distributing session keys.

A brute-force approach involves trying every possible key until an intelligible translation of the ciphertext into plaintext in obtained.

A symmetric encryption scheme has five ingredients: plaintext,encryption algorithm,ciphertext,decryption algorithm and _________.

With _________ encryption the encryption process is carried out at the two end systems.

______ mode is typically used for a general-purpose block-oriented transmission and is useful for high-speed requirements.

It is possible to convert any block cipher into a stream cipher by using the cipher feedback (CFB)mode.

In using encryption,we need to decide what to encrypt and where the encryption gear should be located.

Key distribution can be achieved for two parties A and B by a third party selecting the key and physically delivering it to A and B.

If the analyst is able to get the source system to insert into the system a message chosen by the analyst,then a ________ attack is possible.

_________ is the process of attempting to discover the plaintext or key.

All encryption algorithms are based on two general principles: substitution and _________.