Vault(https://www.vaultproject.io/ https://www.vaultproject.io/) and Phaistos KMS (https://github.com/phaistos-networks/KMS https://github.com/phaistos-networks

Vault(https://www.vaultproject.io/ https://www.vaultproject.io/) and Phaistos KMS (https://github.com/phaistos-networks/KMS https://github.com/phaistos-networks/KMS) both use SSD for sealing/unsealing, where a master key is created, 'divided' into multiple keys and a minimum number of such keys are required to unseal the service.