module ActiveRecord::SignedId

created with the purpose will no longer find the record.
And you then change your +find_signed+ calls to require this new purpose. Any old signed ids that were not

user.signed_id purpose: :v2

version the signed_id, like so:
(or maybe you forgot to set an expiration date while meaning to!), you can use the purpose to essentially
If you accidentally let a signed id out in the wild that you wish to retract sooner than its expiration date

record. If a purpose is set, this too must match.
If the expiration date has been exceeded before +find_signed+ is called, the id won't find the designated
It can furthermore be set to expire (the default is not to expire), and scoped down with a specific purpose.

when passed to +find_signed+ (or raise with +find_signed!+).
the cryptographic signature will no longer match, and the signed id will be considered invalid and return nil
This means that the ID can be decoded by anyone; however, if tampered with (so to point to a different ID),

It's just encoded and protected against tampering.
{the signed id is not encrypted}[link:classes/ActiveSupport/MessageVerifier.html#class-ActiveSupport::MessageVerifier-label-Signing+is+not+encryption].
However, as with any message signed with a +ActiveSupport::MessageVerifier+,
This signed id is tamper proof, so it's safe to send in an email or otherwise share with the outside world.

Returns a signed id that's generated using a preconfigured +ActiveSupport::MessageVerifier+ instance.

def signed_id(expires_in: nil, expires_at: nil, purpose: nil)
  raise ArgumentError, "Cannot get a signed_id for a new record" if new_record?
  self.class.signed_id_verifier.generate id, expires_in: expires_in, expires_at: expires_at, purpose: self.class.combine_signed_id_purposes(purpose)
end