US Patent 11750403 Robust state synchronization for stateful hash-based signatures

In one example an apparatus comprises a computer readable memory, a signing facility comprising a plurality of hardware security modules, and a state synchronization manager comprising processing circuitry to select, from the plurality of hardware security modules, a set of hardware security modules to be assigned to a digital signature process, the set of hardware security modules comprising at least a first hardware security module and a second hardware module, and assign a set of unique state synchronization counter sequences to the respective set of hardware security modules, the set of state synchronization counter sequences comprising at least a first state synchronization counter sequence and a second state synchronization counter sequence. Other examples may be described.