Law No. 5651 on the regulation of publications on the internet and combating crimes committed through these publications obliges organizations to record the traffic occurring on their networks. However, simply keeping logs is not enough; it must be proven that these logs have not been altered and their security is ensured. This is exactly where the concept of log integrity comes into play.
In this guide, we will discuss why log integrity is critical in the 5651 compliance process, covering its legal and technical dimensions.
What is Log Integrity?
Log integrity is a security concept that guarantees that records (logs) generated by systems have not been altered, deleted, or tampered with in any way from the moment they are created.
Under Law No. 5651, for collected DHCP, firewall, and web access logs to have legal evidentiary value, their integrity must be sealed with a time stamp.
Why is Just Keeping Logs Not Enough?
Many businesses think that simply turning on the logging feature on their firewalls or system devices is sufficient for 5651 compliance. However, this is a major misconception.
1. Legal Validity and Evidentiary Value
In the event of a potential cybercrime or illegal transaction, the prosecutor's office or court will ask you to prove who used the relevant IP address. If your logs are not sealed with a time stamp, you cannot prove that these records have not been altered subsequently. Logs without a time stamp are not accepted as evidence in courts.
2. Protection Against Insider Threats
A significant portion of cyber attacks come from the inside, or attackers try to delete log files to cover their tracks after infiltrating the system. Logs that have their integrity ensured and are instantly transferred to a central server and sealed make it impossible for attackers to wipe their traces.
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Technical Steps to Ensure Log Integrity
The fundamental technical steps to consider when building a 5651-compliant logging architecture are as follows:
Centralized Log Management (Syslog/SIEM)
Logs from distributed systems must be collected in a single center. This prevents log loss and accelerates analysis processes.
Time Stamping
Collected log files are summarized in daily or hourly periods (usually using hash algorithms) and signed with time stamps obtained from authorized electronic certificate service providers (like TÜBİTAK Kamu SM in Turkey).
Secure Archiving and Backup
Sealed logs must be securely stored for the period specified in the law (usually 2 years). Backing up this data and protecting it against disaster scenarios is of critical importance.
The Intersection of 5651 and KVKK (GDPR Equivalent)
Log integrity is important not only for 5651 but also for the Personal Data Protection Law (KVKK). Under KVKK, reliable log sources are needed to detect and report data breaches. To understand the relationship between these two laws in more detail, you can read our article titled What is the Difference Between 5651 and KVKK?.
Why is Professional Support Important?
Log management and ensuring integrity is a process that requires continuous monitoring and expertise. An incorrectly configured system can expose your organization to serious legal and financial sanctions.
Within the scope of our Information Security Policy Consulting service, we analyze your organization's network infrastructure and design reliable and sustainable logging architectures that are fully compliant with 5651 and KVKK requirements.
Conclusion
In 5651 compliance, log integrity is not just a technical requirement, but also the most important shield that ensures your organization's legal security. By guaranteeing the immutability of your logs, you can both fulfill your legal obligations and increase your visibility against cyber incidents.
To evaluate your organization's 5651 compliance status and establish a reliable logging infrastructure, please contact us to speak with our expert teams.
