DES Modes summary

1. Electronic Code Book (ECB)
- Should not use to encrypt large data, as patterns would show themselves
- If an error takes place during encryption, it only affects one block of data
- Only usable for encryption of short messages
- a block of plaintext and a key will always give same cyphertext

2. Cipher Block Chaining (CBC)
- does not show a pattern as each block of text, the key and the value based on previous block are processed in the algorithm, and applied to the next block of text
- chaining effect hides any patterns
- CBC mode is great to use when you need to send large chunk of data at a time

3. Cipher Feedback (CFB)
- Combination of block and stream cipher
- Used to encrypt smaller amount of data compared to CBC
- Important to use new IV value to encrypt each new stream of data

4. Output Feedback (OFB)
- In CBC and CFB, if an error is introduced in any cipher block, that will be propagated to all next cyphers, but thats not the case in OFB.
- It extends the keystream for feedback, and not old cipher block as CBC and CFB does

5. Counter Mode (CTR)
- Similar to OFB, but instead of using random IV unique value, uses a IV counter which increments for each plaintext block.
- No chaining involved
- encryption of individual blocks can happen in parallel, which increases the performance
- Its used majorly for performance compared to other modes