Section 2.8 Basics of Cryptographic concepts Flashcards
What do you call the conversion of machine-readable and human-readable communicated information into an unreadable form that keeps the information confidential and private?
Cryptography
The central function of cryptography is _________, the transformation of data into an unreadable form.
Encryption
Encryption ensures _______ by keeping the information hidden from those for whom the information is not intended.
Confidentiality
What transforms encrypted data back into an intelligible form?
Decryption
Cryptography also supports ________ by making systems better able to handle resource constraints.
High resiliency
Cryptographic algorithms and techniques are chosen based on?
The level of protection required and resource constraints
The number of bits that are within an encryption algorithm’s key is?
Key length/size
The set of all possible permutations of a key is the?
Keyspace
Data integrity is maintained by using what cryptologic function?
Hashing
What is often used to create signatures for files that indicate whether a file has been tampered with?
Hashing
What cryptologic function is used to maintain Authentication?
Encrypted digital certificates are used to identify users electronically on a network
By implementing _____________ processes, a cryptographic system can be considered secure for business and legal transactions?
Nonrepudiation
What concept provides security by modifying the data to make it unreadable to a human or program trying to use it?
Obfuscation
A system that provides encryption and decryption services is called a?
Cryptosystem
A cryptosystem uses a mathematical encryption ___________ to turn data into ciphertext?
Algorithm/Cipher
A _______ is like a password that’s combined with an algorithm to create the ciphertext.
key
The strength of an encryption key depends on the algorithm’s what?
keyspace
Most attacks on encryption center on what?
The interception of keys
What concept means that the outcome of the ciphertext is dependent on several parts of the key, rather than only one? This concept increases the change in the plaintext to ciphertext.
Confusion
What concept means that even a small change in the plaintext results in a significant change in the ciphertext?
Diffusion
What type of cipher switches out the plaintext characters with other characters?
Substitution Cipher
What type of cipher rearranges the characters in different places through mathematical formulas?
Transposition Cipher
What encryption scheme has both parties using the same key to encrypt and decrypt?
Symmetric Encryption/Secret Key
The security of Symmetric Encryption depends on?
Users keeping their keys private
A symmetric systems is much faster than asymmetric encryption because what?
The underlying algorithms are simpler and more efficient.
What type of symmetric encryption encrypts data one bit at a time?
Stream Ciphers
What is the most commonly found streaming cipher, found in the Wired Equivalent Privacy (WEP) protocol?
RC4
What type of symmetric encryption encrypts entire blocks of data?
Block Ciphers
What do you call authentication schemes that have been developed to work with block ciphers to provide not only encryption but also authentication?
Authenticated models of operation/Authenticated encryption
What encryption scheme uses 2 mathematically-related, different keys to encrypt and decrypt?
Asymmetric Encryption scheme
What encryption concept involves a 3rd party, such as a government agency or an authorized organization, that holds a special third key used to encrypt the private key, which is then stored in a secure location?
Key escrow
The advantage of an asymmetric scheme over symmetric schemes is that it offers a level of?
Authentication and Nonrepudiation
What kind of cryptosystem uses complex mathematical structures to create secure asymmetric algorithms and keys? Often used as a lightweight solution, provides functionality such as encryption an digital signatures.
Elliptic-curve Cryptography (ECC)
What kind of key exchange takes places within the normal communication channel?
In-band key exchange