ECB: Easiest and fastest mode for block cipher. Weakness: Vulnerable
to replay attacks, easy to cryptanalyze.
For encrypting random data (e.g., keys), ECB is suitable due to short
and random nature of data.
CBC: Generally used for encrypting files.
CFB: Mode of choice for encrypting streams of characters individually.
OFB or CTR: Preferred in error-prone environments due to no error
extension.
BLOCK CIPHERS
ECB
CBC
STREAM CIPHERS
CFB
OFB
Not Prime = Composite, 1 is called “unit”, 0 and all negative are neither prime nor composite
RSA
Elliptic Curve
One Way Hash
Digital Signature