Block encoding does not work

[stevenwood2014]

key = "abcdefghijkmnopqrstuvwxyz123456"
iv = <<62, 9, 192, 172, 116, 137, 208, 6, 250, 199, 117, 47, 177, 123, 252, 87>>
Mcrypt.encrypt("Hello World", :twofish, :cbc, key, iv)

{ :ok, "Hello World" }

For any algorithm using :cbc or :ecb (block modes) the result is always the same plain text string and no actual encoding is done.

Is there a step or configuration that I am missing, or perhaps some other issue at hand?

Thank you.

[seeekr]

Confirmed.