PCI DSS 10.6.1.1: Protect Time Signals from Manipulation
Time synchronization is critical to PCI DSS compliance—inaccurate time signals can compromise audit logs and weaken your security posture. Control 10.6.1.1 requires systems to be protected from receiving manipulated or inaccurate time signals, ensuring reliable timestamp integrity across your environment. Without proper protections, attackers could alter logs and cover their tracks.
What this means
This control mandates that all systems receiving time signals—such as NTP (Network Time Protocol) sources—must be protected from receiving false or manipulated time data. Inaccurate timestamps can invalidate audit logs, compromise forensic investigations, and create compliance gaps. The control ensures time signal sources are authenticated, validated, and monitored to maintain the integrity of system clocks used for logging and security event tracking.
How to comply
- 1.Implement authenticated NTP sources using secure protocols (NTPSec or similar) to prevent unauthorized time signal injection
- 2.Restrict NTP access to trusted, authorized time servers within your network infrastructure
- 3.Monitor time synchronization status and alert on significant clock drift or failed synchronization attempts
- 4.Use cryptographic authentication (symmetric or asymmetric) to validate time signal integrity before accepting updates
- 5.Regularly audit and document all time signal sources and their security configurations
- 6.Implement redundant time sources to detect and reject anomalous or conflicting time signals
- 7.Configure systems to log all time synchronization events and anomalies for audit purposes
Evidence auditors look for
- NTP configuration files showing authenticated time servers and security parameters (e.g., /etc/ntp.conf with restrict and authentication directives)
- Firewall rules limiting NTP traffic to approved authoritative time sources
- System logs showing successful time synchronization and rejected invalid time signals
- Monitoring dashboards displaying clock drift thresholds and synchronization status across systems
- Network packet captures demonstrating encrypted or authenticated NTP exchanges
- Change management records for time source updates and authentication key rotations
- Incident logs documenting detection and response to time synchronization anomalies
Frequently asked questions
When will FAQs be available?
The FAQ for this control is currently being prepared.
GRCWatch automatically monitors NTP configuration across your infrastructure, validates time signal authentication, detects synchronization anomalies, and generates audit-ready evidence—eliminating manual time signal compliance checks and reducing your PCI DSS 10.6.1.1 audit burden.
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