Best Group Key Rotation Interval Setting for Router: 0 or 3600?

I'm curious to know how the "Network Key Rotation Interval" or group key update period feature works in ASUS (and other) routers. I read on a few forums that setting the key to default 3600 seconds will add maximum security; but it will disconnect the network access at regular intervals. That's exactly what's happening on our network at CrazyEngineers and it's little annoying. I found some interesting information about this setting:-

1. It works only for AES encryption or TKIP+AES combo.
Question: Do CEans recommend some other encryption for secure wireless connections?

2. The key is automatically generated from the SSID and the password set for the network. Refreshing of this key does not mean that a new password will have to be entered every hour. However, it results into Internet connection being unavailable for some time at regular intervals.

3. The option can be set to 3600 or 0. If the network is continuously being used for streaming content (and boy, we do play a lot of Gaana.com radio here at CE Headquarters); the recommended setting is 0.

4. I understand that setting the key to a shorter value will strain the hardware. I'm considering setting it to about 2 hours (7200) or more.

Update: Here’s an explanation of the best recommended settings for your WiFi Router.

The optimal group key rotation interval for a router, when faced with options like "0" or "3600", is usually 3600 seconds, or one hour.

This setting strikes a delicate balance between security and performance, offering enhanced protection against compromised keys without severely impacting the throughput and overall performance of the network.

However, it's essential to remember that the ideal setting can vary depending on the specific network's security needs, the nature of the data transmitted, and the anticipated threat model.

Understanding Group Key Rotation Interval

The group key rotation interval setting is part of a wireless network's security architecture, specifically relating to the Wi-Fi Protected Access (WPA or WPA2) protocols.

It determines how often the group temporal key (GTK), used in encrypting broadcast and multicast traffic, is automatically updated or "rotated". Regularly rotating the GTK reduces the risk that an attacker could compromise the key and, consequently, the data being transmitted.

Performance Implications

So why not set the rotation interval to an incredibly short value for maximum security?

The answer lies in the performance trade-off.

The more frequent the key rotations, the more computational resources and bandwidth the router must dedicate to securely disseminating the new key to all connected devices.

This process, if done excessively, can lead to increased latency, reduced data throughput, and overall degraded network performance.

Setting the interval to 3600 seconds (one hour) typically offers a robust level of security without severely impacting network performance.

In contrast, setting the rotation interval to "0", effectively disabling automatic key rotation, could indeed boost network performance but at the expense of potential security vulnerabilities, especially if the network is targeted by a determined attacker.

Default Settings and Router Brands

Interestingly, the default group key rotation interval setting varies across different router brands. Some common brands and their default settings are as follows:

• Cisco: Many Cisco routers default to a 3600-second rotation interval, reflecting the company's balance between robust security and performance.

• Netgear: This brand also tends to default to a 3600-second rotation interval, aligning with industry best practices.

• ASUS: Many ASUS routers default to "0", choosing to prioritize performance over the added security benefits of automatic key rotation.

• TP-Link: TP-Link routers often default to "0", similarly prioritizing performance.

However, these are defaults, and in many cases, administrators can manually change this setting to better suit their specific needs.

The "3600" Advantage: A Balance of Security and Performance

A group key rotation interval of 3600 seconds offers a useful balance for most networks.

It maintains a respectable level of security by changing the encryption key regularly, thus reducing the potential damage if a key is compromised.

Furthermore, it avoids unnecessary strain on the network infrastructure, ensuring that devices can communicate efficiently and that the key rotation process does not introduce significant latency or other performance problems.

Remember, however, that even the most frequent key rotation is no substitute for good overall security practices.

These include using strong, unique passwords; ensuring all devices on the network are secure and updated; and monitoring the network for any signs of malicious activity.

To conclude, while the "3600" setting is generally recommended, network administrators should always assess their unique network environment and requirements.

It's crucial to understand that both options - "0" and "3600" - serve different purposes and cater to various scenarios, underlining the importance of adaptability in the face of dynamic security needs and network conditions.