CISSP Domain 4 – Cryptography Flashcards
ROT13
A more recent encryption method used in the 1980s, ROT13, was really the same thing as a Caesar cipher. Instead of shifting 3 spaces in the alphabet, the encryption process shifted 13 spaces. The idea was that if you were interested in reading something potentially “offensive” you could simply use the shift-13 approach and read the material. Other people who did not want to view it would not be offended.
Cryptanalysis
is the science of studying and breaking the secrecy of encryption processes, compromising authentication schemes, and reverse-engineering algorithms and keys.
Cryptology.
the study of cryptanalysis and cryptography.
• Algorithm
Set of mathematical and logic rules used in cryptographic functions
• Cipher
Another name for algorithm
• Cryptography
Science of secret writing that enables an entity to store and transmit data in a form that is available only to the intended individuals
• Cryptosystem
Hardware or software implementation of cryptography that contains all the necessary software, protocols, algorithms, and keys
• Cryptanalysis
Practice of uncovering flaws within cryptosystems
• Cryptology
The study of both cryptography and cryptanalysis
• Encipher
Act of transforming data into an unreadable format
• Decipher
Act of transforming data into a readable format
• Key
Sequence of bits that are used as instructions that govern the acts of cryptographic functions within an algorithm
• Key clustering
Instance when two different keys generate the same ciphertext from the same plaintext
• Keyspace
A range of possible values used to construct keys
• Plaintext
Data in readable format, also referred to as cleartext
• Substitution cipher
Encryption method that uses an algorithm that changes out (substitutes) one value for another value
• Scytale cipher
Ancient encryption tool that used a type of paper and rod used by Greek military factions
• Kerckhoffs’ principle
Concept that an algorithm should be known and only the keys should be kept secret
