2.8 cryptographic concepts Flashcards
ciphertext
encrypted message
cipher
algorithm to encrypt/decrypt
cryptanalysis
art of encryption cracking
homomorphic encryption
a cryptographic technique that allows computations to be performed on encrypted data without requiring decryption
symmetric encryption
a technique that uses a single key to encrypt and decrypt data
- does not scale well
- very fast to implement
asymmetric encryption
two key system
Public key: Used for encryption
Private key: Used for decryption
Elliptic Curve Cryptography
asymmetric encryption uses curves instead of numbers
Hash Collision
when two different pieces of data produce the same hash value
key exchange
a cryptographic process that allows two parties to exchange keys. This allows them to use the keys to share encrypted information.
Perfect Forward Secrecy
Perfect Forward Secrecy
a type of encryption that automatically and frequently changes the keys used to encrypt and decrypt information.
SSL/TLS feature
more computing power and must be supported by browser
steganography
the practice of concealing information within another message or physical object to avoid detection
message is invisible
- hide message in TCP packets
- embed in image
- invisible watermarks
- audio
- video
cipher stream
one byte at a time
high speed, low hardware
symmetric encryption
cipher block
encrypts a block of bytes at one time
64-128 bits
symmetric encryption
CBC
cipher block chaining
add randomization via IV
initialization vector (IV)
This is a block of bits that randomizes the encryption. It produces distinct ciphertexts even if the same plaintext is encrypted multiple times.
