I found some code to get crypto-js to encrypt data in the browser, and with a pointer from someone on SO, it now decodes data as well.
My next question is about the use of an IV; is an IV like a salt where it needs to be generated from a cryptographically secure RNG, or will any data do like, a timestamp?
And from my reading, an IV does not need to be secret - if your IV is 16 bytes long, you take those 16 bytes, append the text to it that you want to encrypt, and then can publish both the IV and cipher text. Upon decrypting, you would check that the first 16 bytes of plain text match the IV, and then discard them from the resulting plain text.
Am I understanding this correctly? Will any unique data (to each cipher text) be useful for an IV, or should I be looking for a method to generate IV's (on the client side, which means it could potentially be substituted) in a secure manner?
PS - this is for a personal project/learning experience, not a product that's advertised as being secure :)