Returns a jar that’ll automatically generate a signed representation of cookie value and verify it when reading from the cookie again. This is useful for creating cookies with values that the user is not supposed to change. If a signed cookie was tampered with by the user (or a 3rd party), an ActiveSupport::MessageVerifier::InvalidSignature exception will be raised.
This jar requires that you set a suitable secret for the verification on your app’s config.secret_token.
# File actionpack/lib/action_dispatch/middleware/cookies.rb, line 230 def signed @signed ||= SignedCookieJar.new(self, @secret) end