IV
Initialization Vector
A random value that ensures identical plaintext encrypts differently each time.
An IV is a non secret but unique value fed into encryption so that identical plaintext does not produce identical ciphertext, defeating pattern analysis. It is essential for block cipher modes like CBC and for stream ciphers, where reuse can be catastrophic. The classic example is WEP, whose short, repeating IVs allowed attackers to recover the key. Best practice requires IVs to be random or non repeating, and unlike a key the IV does not need to stay secret.
Initialization Vector: a random "starter" so identical plaintext encrypts differently each time.
Looking IV up is step one. Getting tested on it is step two.
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