Precision Time Protocol, defined in IEEE 1588, is a network protocol that synchronizes clocks with very high precision. It is used where timing must be tight and shared across many devices, such as industrial control, telecom, and measurement systems. PTP works by selecting a reference clock, often a grandmaster, and distributing time to other devices so logs, control actions, and sensor data stay aligned.
PTP matters in cyber security because time is part of system integrity. If an attacker delays packets, creates path asymmetry, or forges timing messages, devices can drift from the real reference without an obvious outage. That can confuse event ordering, protection logic, and forensic records. Defenders monitor offset, delay variation, and grandmaster behavior, and they often use redundant time sources, authenticated timing, and holdover capability to resist disruption. In OT environments, PTP is not just a convenience; it is a control dependency that must be protected.