2.8 Summarize the basics of cryptographic concepts. Flashcards
Cipher Text
encrypted message
Cipher
Algorithm used to encrypt and/ or decrypt
Cryptanalysis
Finding vulnerabilities in ciphers
Crypto graphic Key
A KEY added to the end the cipher to encrypt it.
Key Stretching
encrypting a key multiple times to strength the key.
Bcrypt
Key stretching library
PBKDF2
Key stretching library
Lightweight cryptography
Used for IoT cryptography that has limited resources to encrypt
Homomorphic encryption (HE)
Preform calculations on a algorithm with decrypting the data.
Saves the encrypted result.
Symmetric Encryption
(Shared Secret)
Only using one key to decrypt and encrypt data.
If the key becomes known to unauthorized parties then you have to redo your encryption.
Asymmetric Encryption
Two or more different keys Public and Private.
Private Key and Public Key
Key you only have and a key everyone can see
Both mathematically related
EEC
Elliptic curve cryptography
IoT use curves for Asymmetric encryption because they don’t have the computing power for it
Digital Signatures
Cryptography/encryption combined with Hashing
Authentication non-repudiation, and integrity
Collison
When two hashes have the same out put
SHA256
Hash Algorithm
Salt
Added data added to a Hash.
Users that have the same password have the same hash. adding Salt combat that
Key Length
Longer a Key the stronger the key
Asymmetric 3,072 bit
Symmetric key 128 bit
Key exchange
Out-of-band - transfer/sending a key off the Network
In-band - Sending a key on the Network
Ephemeral Key
A key that is only used once.
PFS
Perfect Forward Secrecy
A system that allows you not be compromised by not using the same key twice ever.
Prevents people from getting your server key.
Steganography
Hide code code through a image, audio, video.
Not a true secure message.
Quantum Computing
Computing- doesn’t use bit like regular computer. Quantum computing uses Qubits and the value is between 0-1.
Post-Quantum
Current Algorithm that we you today for cryptography can be easily solved by quantum computers.
NTRU slows down quantum cryptography
Quantum Communication or
QKD
Quantum Key Distribution-
Creates unbreakable encryption that you can send in the network without being decrypted.
If there is eavesdropping the key would authenticate.
Stream Ciphers
Encrypts one bit/byte at a time
Symmetric encryption
Block Cipher
Encrypts a entire block
if there isn’t a enough data the data will be added to make a 64 byte (Padding)
Modes of Operation
ECB
Electronic Code Book
uses a single Encryption key and uses that for each identical plaintext block encryption
CBC
Cipher Clock Chaining
Right before Plaintext block is “keyed” a IV (initialization vector) is added before hand.
After that the cipher block is then used in the same place as the IV.
This allows randomization
CTR
Counter or Counter Mode
Top: Unencrypted Counter
Second: Key
Third: Plaintext added to the block
Bottom: Cipher Text
GCM
Galois/Counter Mode
Adding authentication the mode of operation
Block Chain
A list of records, when something is added it is done by a cryptographic algorithm
Resistant to modification
