iv=

        # OpenSSL::Cipher.iv=

(from ruby core)
### Implementation from Cipher
---
    cipher.iv = string -> string

---

Sets the cipher IV. Please note that since you should never be using ECB
mode, an IV is always explicitly required and should be set prior to
encryption. The IV itself can be safely transmitted in public, but it
should be unpredictable to prevent certain kinds of attacks. You may use
Cipher#random_iv to create a secure random IV.

Only call this method after calling Cipher#encrypt or Cipher#decrypt.