The Atomic Cryptographic Extension (ACE) is an ISA extension to enable secure cryptographic implementations. ACE separates key provisioning from key usage, enabling distinct environments to perform the two functions. For example, keys could be delivered to user software by a TEE applet. Unlike existing round-based AES extensions, which inherently expose key material, ACE performs cryptographic operations atomically. Keys are associated with metadata that ties them to specific algorithms and usage policies. Keys and metadata are bonded to each other by writing them in Context Registers (CRs). The contents of CRs can only be exported in encrypted and authenticated form for secure re-import, enabling secure context switches and VM migrations. ACE is work in progress of the High Assurance Cryptography (HAC) TG of RISC-V International.