Problem

True wall-clock synchronization across decentralized agent nodes is impossible (due to network latency and NTP drift). However, we must globally order A2A interactions so that cryptographic receipt chains are causally correct.

Approach

Implement Hybrid Logical Clocks (HLC) in the Mindburn A2A Protocol. This combines physical clock timestamps (for human readability and coarse-grained sync) with an incremental logical counter. When a receipt is formulated, its HLC timestamp guarantees causality (happens-before ordering) even if wall clocks skew.

Invariants

HLC(event2) > HLC(event1) if event1 caused event2.
Receipt graphs cannot form causal cycles.

Artifacts

Zero Trust Interaction Protocol

References

Kulkarni et al. (2014). Logical Physical Clocks and Consistent Snapshots in Globally Distributed Databases.

Exploratory: HLC drift constraints and clock jumps.