Domain 3: Security Architecture and Engineering Flashcards
Algorithm
A mathematical function used in the encryption and decryption processes. It may be quite simple or extremely complex. Also defined as the set of instructions by which encryption and decryption is done.
Asymmetric Encryption
Process that uses different keys for encryption than it does for decryption, and in which the decryption key is computationally infeasible to determine given the encryption key itself, from plaintext and corresponding ciphertext, or from knowledge of the key generation or encryption algorithm.
Block Mode Encryption
Using fixed-length sequences of input plaintext symbols as the unit of encryption.
Ciphertext
The altered form of a plaintext message so as to be unreadable for anyone except the intended recipients. In other words, it has been turned into a secret.
Collision
This occurs when a hash function generates the same output for different inputs. In other words, two different messages produce the same message digest.
Crime Prevention Through Environmental Design (CPTED
An architectural approach to the design of buildings and spaces, which emphasizes passive features to reduce the likelihood of criminal activity
Cryptanalysis
The study of techniques for attempting to defeat cryptographic techniques and, more generally, information security services.
Cryptographic Hash, Cryptographic Hash Function
A process or function that transforms an input plaintext into a unique value called a hash (or hash value). These do not use cryptographic algorithms; the term “cryptographic” refers to the assertion that strong hash algorithms are one-way functions; that is, it is computationally infeasible to determine the input plaintext from the hash value and knowledge of the algorithm alone. Message digests are an example of the use of a cryptographic hash.
Cryptography
The study or applications of methods to secure or protect the meaning and content of messages, files, or other information, usually by disguise, obscuration, or other transformations of that content and meaning.
Cryptosystem
The complete set of hardware, software, communications elements, and procedures that allows parties to communicate, store information, or use information that is protected by cryptographic means. The system includes the algorithm, key, and key management functions, together with other services that can be provided through cryptography.
Cryptovariable
One or more parameters inherent to a particular cryptographic algorithm and its implementation in a cryptosystem. Block size, key length, and number of iterations (or rounds) are examples.
Decoding
The reverse process of encoding, converting the encoded message back into its plaintext format.
Decryption
The reverse process of encryption. It is the process of converting a ciphertext message back into plaintext using the cryptographic algorithm and appropriate key for decryption (which is the same for symmetric encryption, but different for asymmetric encryption). This term is also used interchangeably with “deciphering.”
Encoding
The action of changing a message or other set of information into another format using a code. Unlike encryption, which obscures or hides the meaning, encoded information can still be read by anyone with knowledge of the encoding process.
Encryption
The process and act of converting the message from its plaintext into ciphertext. Sometimes it is also referred to as enciphering. The two terms are sometimes used interchangeably in literature and have similar meanings.
Encryption System
The total set of algorithms, processes, hardware, software, and procedures that taken together provide an encryption and decryption capability.
Frequency Analysis
A form of cryptanalysis that uses the frequency of occurrence of letters, words, or symbols in the plaintext alphabet as a way of reducing the search space.
Hybrid Encryption System
A system that uses both symmetric and asymmetric encryption processes.
What are the encryption systems? symm and Asymm
In Band
Refers to transmitting or sharing control information, such as encryption keys and cryptovariables, over the same communications path, channel, or system controlled or protected by that information.
Key
The input that controls the operation of the cryptographic algorithm. It determines the behavior of the algorithm and permits the reliable encryption and decryption of the message.
Key Escrow
A process by which keys (asymmetric or symmetric) are placed in a trusted storage agent’s custody for later retrieval. The trustworthiness of the encryption system(s) being used is thus completely placed in the escrow agent’s control.
Symmetric cryptosystem
use a shared secret key available to all users of the cryptosystem
Integrity
ensures that data is not altered without authorization
Digital signatures
Message integrity is enforced through the use of encrypted message digests
a recipient can verify the message digest is valid and data not altered in transit