Cryptography Flashcards
What is Salting?
A cryptography technique.
Salt is a fixed length, cryptographically strong random value.
Salt is added to the input of hash functions to create unique hashes.
Salt makes hash function look non-deterministic.
Once salt is added, it can be hashed to create a random hash.
If two users have the same password, it doesn’t reveal password duplicates through hashing.
What is DES?
How many bits does it use?
Is it secure?
Data Encryption Standard
Messages in blocks of 64 bits.
Key of 56 bits.
Not secure - was cracked via a brute force attack.
What is asymmetric encryption?
Approach where user has 2 keys, one is public and one is private.
Public key is distributed freely.
Person encrypts outgoing message using receiver’s public key.
Only receiver’s private key can decrypt it.
What is PEM and PGP?
Which cryptosystems do they use?
PEM: Privacy Enhanced Mail. Uses 3DES symmetric key and standards to function with public key cryptosystems.
PGP: Pretty Good Privacy. Uses IDEA cipher for message encoding (sign, encrypt, decrypt emails)
What is SSL? What is S-HTTP?
How do they work?
SSL: Secure Socket Layer protocol: uses public key encryption to secure a channel over the internet.
S-HTTP: Secure Hypertext Transfer Protocol: application of SSL over HTTP, encrypts information passing between computers through protected and secure virtual connections.
