Week 6- Principles of cryptography: fundamentals and symmetric systems Flashcards
What is Cryptology?
the science of secure communications
what is cryptanalysis?
the study of encryption to detect vulnerabilities and propose cryptographic techniques.
what is cryptography?
encode and decode information for secure communication.
achieves confidentiality and integrity of CIA triad.
what is a block cipher?
a cryptographic method, data is broken into smaller blocks for encryption and decryption using a cryptographic key
what is a cryptographic key?
a numerical value that act as an input to encryption/decryption algorithm.
what is AES?
advanced encryption standard.
symmetric block cypher used across the internet and wi-fi networks.
Define Diffie-Hellman (DH)
a key exchange, mathematical algorithm whereby two entities can share a symmetric key remotely.
what does Moore’s law predict?
that computer power and its ability to crack a code doubles every 18 months.
define brute-force-attack
an exhaustive cryptanalytic method, attempts every possible key/password combination until on works.
what is 3DES?
3 digital encryption standard
symmetric block cipher with key length 112 or 168 bits.
Define reverse engineering
using the output of a device/system to figure out how it works
What is a dictionary attack?
an attempt to break into a password protected system by using a list of well-known words or phrases.
define digital signature
authenticating the authorship of a message
define digital certificate
proof of ownership of a public key
define public key
asymmetrical cryptographic key available to anyone
Define web of trust
an arrangement of entities where there is a relationship of trust
define plaintext
unencrypted information
define ciphertext
encrypted information
define a cipher or cryptographic algorithm
mathematics responsible for turning plaintext to ciphertext or reverting it back plaintext
define encryption
the process of converting plaintext to ciphertext
define cryptographic key
a numerical value with a string of bits of specific size used to encrypt or decrypt
define encryption key
a cryptographic key, a piece of information used with an algorithm (cipher) to turn plaintext to ciphertext
(decryption key does the opposite)
define symmetric cryptography
encryption and decryption use the same cryptographic key
define asymmetric cryptography
encryption and decryption use different keys
define decryption
the act of taking a encrypted message and rendering it readable
ciphers can be categorised into 2 types, what are they?
block cipher
divides plaintext into fixed lengths of bits (3DES)
stream cipher
a symmetric method, bits are encrypted one at a time for streaming audio/video
define initialisation vector
the value required in the generation of a block or stream cipher, should not be easily predicted
what is CSPRNG
cryptographically secure pseudo random number generator
an algorithm that produces random numbers, may rely on environmental changes
what is stenography
The study of hiding information inside other information – often in a picture or audio file.
