Key Manager

Key managers are particular to ParaTimes, thoughmnultiple ParaTimes can choose to use the samne kevmanager code.The key manager is responsible fotmaintaining control over the cryptographic keys usedto protect confidential contract state.

The properties that key managers should provide are:

• Confidentiality. The confidential smart contractstate must remain confidential. Generally, thismeans that only authorized, attested ParaTimecompute nodes can access the keys, and imnpliesthat proper cryptographic protection is used forcommnunications between the key managers andthe ParaTime compute nodes.

• Availability. The keys are needed to execute confi-dential contracts.and the key managers must provide enough availability (through replication to geographically separated nodes in different faultzoneg) for the ParaTime. This also implies theintegrity of the key store as well as communication security, since destruction of the key store ogetting the compute nodes to process contract in-vocations with a bad key would severely damagethe contract state.