How do I add validation fields to the end of the survey URL?

For example: MD5 or HASH

www.example.com/index.php?status=S&useri...id}&pid={SID}&token=

{MD5(25055fdsafdsa)}

LimeSurvey ExpressionManager (AKA ExpressionScript) is not offering these functions.

Maybe can be done in plugin, but i don't understand what validation that can be done and when ?
If it's the redirect : simple usage of afterSurveyComplete www.limesurvey.org/manual/AfterSurveyComplete

DenisChenu wrote: Maybe can be done in plugin, but i don't understand what validation that can be done and when ?

Looks like certain plaintext variables should not be exposed via URL.
E.g. a emailadress or code. Hashing that data and comparing the hash in the other application (EndURL) might be the idea.

jelo wrote: …EndURL…

It's the reason why i put a link to afterSurveyComplete event : done for this (you can call to directly the external script via a curl call : then nothing are shown in URL