Based on the Helicopter Racing League (HRL) case study, your team is in charge of creating a payment card data vault for card numbers used to bill tens of thousands of viewers, merchandise consumers, and season ticket holders. HRL wants to expand their predictive capabilities and reduce latency for their viewers in emerging markets. You need to implement a custom card tokenization service that meets the following requirements: * It must provide low latency at minimal cost. * It must be able to identify duplicate credit cards and must not store plaintext card numbers. * It should support annual key rotation. Which storage approach should you adopt for your tokenization service?