Secure Fields protects card details at checkout

Secure Fields is a set of iframe fields to record card data at checkout and process them securely through Mercado Pago servers. This functionality will allow your store to stop dealing with information encryption, and it will also facilitate your PCI SAQ-A certification process. Secure Fields is currently not available in SDK JS V1 and to get it automatically you will need to migrate to SDK JS V2.

Check out the documentation and make your migration now.