class Rack::Session::Cookie

def secure?(options)

set to true
* Customer :coder is used, with :let_coder_handle_secure_encoding
* The legacy HMAC option is enabled
initialized
* Encrypted cookies are enabled and one or more encryptor is
Were consider "secure" if: 
def secure?(options)
  !@encryptors.empty? ||
    @legacy_hmac ||
    (options[:coder] && options[:let_coder_handle_secure_encoding])
end