Visa and MasterCard  should plan to transition from variant format encryption to key block format encryption. The ability to perform key exchanges with Visa and Master Card in variant format will not be supported by Visa  and MasterCard after June 2021.

Visa and MasterCard  is making changes to its systems to comply with this new requirement. Stakeholders and business partners must be aware of these changes and evaluate their impact, and potentially make changes to their existing implementations, to ensure there is not an interruption of services.

Once Visa and MasterCard discontinues support for variant format key exchange, it is critical that clients have migrated to key block format key exchange if they wish to exchange keys with Visa and MasterCard. The ability to perform key exchanges with Visa and MasterCard in the variant format will not be supported after the June 2021 date.

Visa Support for Key Exchange in Key Blocks Format

MasterCard Support Cryptographic Key Blocks Format

For More Detail Information Key Blocks Format – from pcisecuritystandards.org