LP - Practical Cryptography Flashcards
Practical Cryptography
Symmetric key encrypting uses the same
key to encrypt and decrypt
Popular symmetric key encryption are
AES-CBC-129/256 and AES-GCM-128/256
Symmetric encryption two types of ciphers
- block
- stream
Some common block ciphers are
DES
3DES-EDE
AES-CBC
AES-GCM
Blowfish
Stream ciphers work in plain stream bits and are
XORed
Some common stream ciphers are
FISH
CryptMT
Scream
Cryptographic hashing
PKI stands for
public key infrastructure
Asymmetric Keys are slower or faster than symmetric keys
slower
Popular Asymetric (Public Key) algorithms are
RSA (Rivest-Sharmir-Adleman) most widely used
Diffie-Hellman
ECC (Elliptic curve cryptography)
DSA (Digital signature algorithm
Diffie-Hellman key exchange is a protocol for securely exchanging cryptographic keys over an
untrusted network
FDE stands for
full disk encryption
In full disk encryption (FDE)
the master boot record (MBR) is not encrypted
Cryptographic Hashing is a one-way mathematical function that produces a digest of length?
128 to 512 bit
Cryptographic Hashing converts data of any input size to a fixed-length string called a
- hash value
- message digest
- fingerprint
Cryptographic hashing is an advanced version of a simple
checksum
Cryptographic hashing is subject to the
birthday paradox and avalanche effect
Because of the birthday paradox a cryptographic hash is only half as strong as its
bit size
The avalanche effect is
if even one bit is flipped in the origin data the fixed-length hash will be completely different, like an avalanche.
Cryptographic hashing must be collision resistance therefor we do not use
MD5
Salting is the technique of
adding pseudorandom data to a cryptographic hash function
HMACs stands for
Hash-based Message Authentication Codes
Diffie-Hellman is found in
SSH2, TLS and IPSec
Diffie-Hellman key exchange (DHKE) and RSA key transport are used for
establishing secret keys between two parties over an unsecured channel
How does Diffie-Hellman (DH) use the secret key?
Both parties use it all of the time
