# Method Nettle.CHACHA()->State()->set_iv()

Method set_iv

  ``object` set_iv(`string(8bit)` `iv`)`

Description

  Set the initialization vector (aka nonce) and reset the block counter to zero.

Parameter `iv`

  An 8-byte long string which is only to be used once for every key.

Note

  This function MUST be called in addition to `set_encrypt_key()` or `set_decrypt_key()`.

Note

  The same `iv` should NEVER be reused with the same key!