TR-34
The ANSI X9 standard for distributing symmetric keys to payment terminals and ATMs using asymmetric cryptography instead of people with clipboards.
For a long time an ATM's master key was loaded by two trusted employees who travelled to the machine and each typed in one key component, so neither ever knew the whole key. It is secure, expensive and scales terribly. TR-34, published in 2012, replaces the road trip with a protocol: a key distribution host (KDH), in practice an HSM, encrypts the key under the receiving device's public RSA key and signs the package.
Both sides are identified by certificates from a shared CA, and the messages are wrapped in CMS. TR-34 handles transport; how the key is then labelled and stored inside bank HSMs is typically the job of TR-31 key blocks. That the standard got such an unglamorous name is practically a mark of quality in the payments industry.