What is log retention?

Logs can be a gold mine of information for your organization. When properly managed, they can help you understand system behavior (of both your application components and your users), comply with regulations, and even prevent future attacks.

Log retention refers to how organizations store log files relating to security and for how long. It is a significant part of log management, and it’s integral to your cybersecurity. If you approach log retention thoughtfully and strategically, you’ll set yourself up for success when it comes to regulatory compliance, effective security analysis, and operational efficiency.

In this post, we'll cover the core concepts of log retention, explore its importance in legal compliance and security, and look at what you must consider when implementing a log retention strategy.

Core concepts

Log retention deals with how organizations store log files and for how long. Log files are generated by various systems, architecture components, and applications across environments. Each of these various types of logs serves a unique purpose:

• System logs: System logs are generated by the operating system. They’re often used for troubleshooting hardware and software issues.
• Application logs: Application logs come from specific software applications. They can be useful for debugging application-specific issues or monitoring application activity.
• Security logs: Security logs record security-related events — such as logins, accessing certain resources, or performing administrative actions — and are crucial for incident response and compliance.
• Audit logs: Audit logs track changes and access to data, which is often required for regulatory compliance.

Importance of log retention

Log retention can serve many purposes in an organization. Certainly, it’s related to maintaining a historical record for troubleshooting incidents and performance monitoring. But the role of log retention in cybersecurity is even more critical. In this section, we'll focus our attention on the critical role of log retention within the context of cybersecurity.

Legal compliance is often one of the first things that comes to mind when discussing log retention. Many industries have stringent regulations that mandate the retention of specific types of logs for a set period. When organizations fail to comply, they can face severe fines and legal repercussions. This makes log retention not just a best practice but a legal necessity.

When it comes to security, log retention plays many roles. AI-native analysis of retained logs can establish baselines of normal activity. Couple these insights with real-time monitoring of logs, and your cybersecurity platform can identify anomalies that might indicate a security incident in progress. Used this way, logs serve as an early warning system for threat detection.

Retained logs provide an audit trail of actions, assisting security teams with incident investigations. They can trace back the steps of an attacker and better understand the scope of an incident.

Finally, in threat hunting, organizations can proactively analyze retained logs to identify signs of compromise that may have been initially overlooked. This approach enables preemptive action against potential threats.

We’ve seen what log retention is and why it’s important. Let’s shift our focus to what enterprises must bear in mind if they want to implement an effective log retention strategy.

Key considerations in building a log retention strategy

A strategic and well-thought-out log retention plan can save your organization from legal troubles and help protect you from security risks. When choosing a log management solution and crafting a log retention strategy, here are some key factors to consider:

Log retention policies

Your log retention policy is the backbone of your strategy. It outlines how long each type of log should be stored and what happens when it reaches the end of its retention period. Tailor your policy to meet both legal requirements and operational needs.

For example, a healthcare organization might be required to retain security logs for one year, whereas audit logs related to patient data should be kept for seven years.

Storage solutions

The log storage solution you choose is also important. On-premises storage gives you more control but can be costly and challenging to scale. On the other hand, cloud storage offers unlimited scalability and is often more cost-effective. Some organizations opt for hybrid solutions, leveraging both on-premises and cloud storage to meet their specific needs.

For most organizations, cloud storage is the way to go.

Security concerns

When you’re thinking about log retention, security should be your top priority. Ask the following questions:

• Do you have access control measures in place? Only authorized personnel should have access to view logs.
• Which types of log files should be stored with encryption measures in place? This is an especially important consideration for logs containing sensitive information.
• What steps do you need to take to ensure the integrity of your logs? For example, cryptographic hashes can be used to verify that logs haven't been tampered with.

Search performance

Considering the sheer volume of log data that will be available to you, the ability to quickly search through your logs is essential. This is particularly salient when it comes to incident response. A good log management solution should offer powerful search capabilities to help you find the information you need without delay.

Latency or ingestion delays

To have timely incident response and analysis, you need real-time or near-real-time log ingestion. If there are significant delays in log ingestion, you’ll be hamstrung in your ability to quickly respond to security incidents. Choose a log management solution that minimizes latency.

Scalability

As your organization grows, so will the volume of your logs. Will the log retention solution you choose be able to accommodate this growth? Consider solutions that can easily scale to handle increasing data loads without completely overhauling your existing system.

Cost

Although it's tempting to choose the most feature-rich solution, cost-effectiveness is perhaps the most important consideration. For some log management solutions, storage costs can escalate quickly, especially for long-term retention. Look for a solution that offers a good balance between features and low total cost of ownership.

Seamless integration

To be most effective, your log retention system must not exist in isolation. It should easily integrate with other tools in your cybersecurity tech stack. Even better, it should be extensible, allowing you to enhance it with features like automation, AI-native analytics, and threat intelligence.

Taking the next steps for log retention

With critical roles in legal compliance and security operations such as threat detection and incident investigation, log retention is essential to an effective cybersecurity strategy. Log retention is a key aspect of log management, requiring enterprises to carefully consider solutions.

If you’re looking for a centralized log management and next-gen security information and event management (SIEM) solution, CrowdStrike^® Falcon LogScale™ might be the right solution for you. Falcon LogScale revolutionizes threat detection, investigation, and response by uncovering threats in real time, accelerating investigations with blazing-fast search, and collecting up to one petabyte of data a day for boundless visibility. With Falcon LogScale, you can log everything to answer anything in real time — all while saving up to 80% compared to legacy SIEM solutions.

When you’re ready to take the next step in cybersecurity for your organization, sign up to try the CrowdStrike Falcon^® platform for free. Alternatively, you can contact CrowdStrike directly to learn more.