Encrypt ID on front-end and decrypt on back-end

Question

I have a front-end form that posts through the ID of a particular element/entry to a back-end controller. Is there any way to encrypt/hash that ID on the front-end, so the plain ID number is not visible, and then decrypt that ID in the back-end controller?

Answer 1

<input type="hidden" name="foo" value="{{ 'bar'|hash }}">

and then in your controller:

if (($foo = craft()->request->getPost('foo')) !== null)
{
    $foo = craft()->security->validateData($foo);
}

at which point $foo will either be null (not present), false (present but tampered with), or a string (present and valid)

Answer 2

I've used hashids successfully before, then create a small plugin helper with a twig filter that transforms the id into a hash that also decrypts it. you can include composer to craft plugins by just updating your composer file and adding hashids to it.