Tokenizing the URL Parameters

Overview Securing Form URLs

Overview

Consent Forms allow URL parameters to be passed. Values specified in these parameters are pre-populated in the Consent Form while rendering the form. These values are however in clear text and can be changed by consumers. Consent Form URL can also be accessed by scripts that submit consents repeatedly and overwhelm the system. Tokenizing the URL parameters helps avoid these types of attacks and fraudulent consents.

Customers can send the URL parameters to a CPM API which returns the token for these parameters. Customers can then send this token as a URL parameter while rendering the form. Four different options are supported for the Consent Forms:

Securing the Consent Form URL

Always use a token – If this option is set, a token must be sent while calling the form. An error is displayed if a token is not passed. This is the most secure option that stops any impersonations and fraudulent consents.

No token required – Token is not required to display the Consent Form. Any URL parameter can be passed directly in the Consent Form URL. If the token is passed, only the token will be considered and all other URL parameters are not considered. This is the least safe option and should not be used by customers.

Only brand, Form ID and Channel can be used without token – Brand, Form ID and Channel can be sent as URL parameters. Rest of the URL parameters will be ignored if passed in the consent form URL. If the token is passed, only the token will be considered and all the other parameters are ignored. This is not very secure and allows fraud consents and attacks.

Any non-identifier field can be used without a token – Any identifier that is not a Data Subject identifier can be sent as URL parameters. If the token is passed, only the token will be considered and the rest of the parameters in the URL are ignored. This is not very secure and allows fraud consents and attacks.

Note that URL Parameters will not be ignored if a token has LatestPreference=True. Whatever is added outside the token with the latest preference parameter set to true has the higher priority. If both fields are found in the token and parameter, CPM takes the token as priority. This works for the "No token required" and "Any non-identifier field can be used without a token" options. In addition, if the latest preference parameter is set to true in the token and a parameter with flag is added outside the token, which is in the parameter but not in the token, the output considers the flag and adds the latest preference.

You can set the following parameters under the URL Condition section on the Publish page.

You can set tokenized URL and non-tokenized URL parameters together in the conditions detailed below:

When the URL Condition in the Publish page is set to "Always use token," if a URL parameter is passed, the system ignores it.

When the URL Condition in the Publish page is set to "No token required with any parameters," if the token is passed with a URL parameter, the system ignores the URL parameter if it is already part of the token and considers it if it is not part of the token. Note that in this case, it does not matter whether a non-tokenized parameter is an identifier or a non-identifier.

When the URL Condition in the Publish page is set to "Any Non-Identifier Field can be used without token," and if a URL parameter is passed along with the token, the system ignores it if it is already part of the token or if it is an identifier. The system considers it if it is not part of the token and a non-identifier field.

When the URL Condition in the Publish page is set to "Only Brand, Form ID and Channel can be used without token," and if any URL parameter is passed with token, the system ignores it. However, if that URL parameter is "channel=email" then the system considers it if the channel is not yet part of the token parameter.

Click the Secure Form button to see an example usage on setting up a tokenized URL parameter.

To obtain tokens for URL parameters, customers can use POST request to https://cpm.trustarc.com/server/api/v1/external/consent-forms/tokenize-params. Parameters to tokenize are sent as payload (request body) in JSON format. This information is provided in the Consent Form as well.

TrustArc  ·  Securing the Consent Form URL  ·  trustarc.com