To minimize the risk of exposing sensitive data such as credit card information while still allowing it to be converted back to its original value when necessary, tokenization is the most effective approach. Tokenization replaces sensitive data with a non-sensitive equivalent, called a token, which has no exploitable value. This method ensures that the original sensitive data is stored securely and only accessible through a secure tokenization system.

In this scenario, applying a tokenization policy at the API Gateway ensures that sensitive information is replaced with tokens before the data leaves the trusted boundary. This minimizes the risk of matching sensitive data to the original. When the original data is needed, the tokenization system can detokenize the token back to its original value securely.

MuleSoft Documentation on Tokenization