Method Nettle.CHACHA()->State()->set_iv()
- Method set_iv
 objectset_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()orset_decrypt_key().- Note
 The same
ivshould NEVER be reused with the same key!