ID is a unique CHURP identifier within the key manager runtime.
MayJoin is the vector of enclave identities that may form the new committee in the next handoffs.
Optional
may_MayQuery is the map of runtime identities to the vector of enclave identities that may query key shares.
MayShare is the vector of enclave identities from which a share can be obtained during handoffs.
RuntimeID is the identifier of the key manager runtime.
Serial is the monotonically increasing policy serial number.
PolicySGX represents an SGX access control policy used to authenticate key manager enclaves during handoffs and remote client enclaves when querying key shares.