Investigating the Effects of TLS 1.3 on Corelight Logs, Part 2

By Richard Bejtlich, Principal Security Strategist, Corelight Introduction Welcome to part 2 of my three-part series on TLS. In the previous article I briefly introduced TLS, and showed how Corelight would produce logs for a clear-text HTTP session. In this article I will perform the same transaction using TLS 1.2, and compare the logs with […]

Investigating the Effects of TLS 1.3 on Corelight Logs, Part 1

By Richard Bejtlich, Principal Security Strategist, Corelight Introduction I’ve written previously about Corelight data and encryption. I wanted to know how TLS 1.3 would appear in Corelight data, and compare the same network conversation over clear-text HTTP, TLS 1.2, and TLS 1.3. In this first of three parts, I will introduce TLS and demonstrate a […]

How Zeek can provide insights despite encrypted communications

By Anthony Kasza, Security Researcher, Corelight Labs Overview Encrypted communications are ubiquitous. While encryption provides confidentiality, it cannot prevent all means of traffic analysis. Certain protocols, such as SSH and TLS, ensure contents are not directly readable by monitoring systems. However, analysis of size and order of transmitted data can provide grounds for inference. This […]

Examining aspects of encrypted traffic through Zeek logs

By Richard Bejtlich, Principal Security Strategist, Corelight In my last post I introduced the idea that analysis of encrypted HTTP traffic requires different analytical models. If you wish to preserve the encryption (and not inspect it via a middlebox), you have to abandon direct inspection of HTTP payloads to identify normal, malicious, and suspicious activity. […]

Network security monitoring is dead, and encryption killed it.

By Richard Bejtlich, Principal Security Strategist, Corelight This post is part of a multi-part series on encryption and network security monitoring. This post covers a brief history of encryption on the web and investigates the security analysis challenges that have developed as a result. I’ve been hearing this message since the late-2000s, and wrote a […]