Chapter 4: Applied Cryptography Flashcards
a well-ordered collection of unambiguous and effectively computable operations that, when executed, produced a result and halts in a finite amount of time.
the art of achieving security by encoding messages to make them non-readable.
Cryptography
the science of encryption, which encompasses cryptography and cryptanalysis.
Cryptology
the process of making and using codes to secure the transmission of information.
Cryptography
the process of obtaining the plaintext message from a cyphertext without knowing the keys.
Cryptanalysis
the person who attempt to break a ciphertext.
Cryptanalyst
an encryption method or process encompassing the algorithm, keys, and procedures to perform encryption and decryption.
Cipher
the process of using the key to produce a ciphertext.
Encryption
the process of using the key to produce the plaintext from the ciphertext.
Decryption
info used in cipher known only to the sender / receiver.
Key
is the original unencrypted text.
Plaintext
3 DIMENSIONS OF CLASSIFYING CRYPTOGRAPHIC SYSTEMS
- Type of Operation Used
- Number of Keys Used
- Way of Processing Plaintext
2 POPULAR CRYPTOGRAPHIC ALGORITHMS
- Substitution (Confusion)
- Transposition (Diffusion)
replaces one or more character with other characters.
Substitution (Confusion)
4 TYPE OF SIBSTITUTION (CONFUSION) ALGORITHM
- Monoalphabetic Cipher
- Caesar Cipher
- Playfair Cipher
- Polyalphabetic Cipher
also known as a simple substitution cipher, relied on a fixed replacement structure.
Monoalphabetic Cipher
also known as the shift cipher.
Caesar Cipher
the best-known multi-letter encryption, it treats diagram in the plaintext as single units and translates these units into cipher diagram.
Playfair Cipher
is any cipher based on substitution, using multiple substitution alphabets.
Polyalphabetic Cipher
uses a simple form of polyalphabetic cipher
Vigenère Cipher
A type of cryptographic algorithm that rearrange one or more character within the text.
Transposition (Diffusion)
involved writing the plaintext out in rows, and then reading the ciphertext out of in columns one by one.
Simple Columnar Transposition
