Timeless Timing Attacks

Presented at DEF CON 29 (2021), Aug. 8, 2021, 1 p.m. (45 minutes).

25 years ago, the first timing attacks against well-known cryptosystems such as RSA and Diffie-Hellman were introduced. By carefully measuring the execution time of crypto operations, an attacker could infer the bits of the secret. Ever since, timing attacks have frequently resurfaced, leading to many vulnerabilities in various applications and cryptosystems that do not have constant-time execution. As networks became more stable and low-latency, it soon became possible to perform these timing attacks over an Internet connection, potentially putting millions of devices at risk. However, attackers still face the challenge of overcoming the jitter that is incurred on the network path, as it obfuscates the real timing values. Up until now, an adversary would have to collect thousands or millions of measurements to infer a single bit of information. In this presentation, we introduce a conceptually novel way of performing timing attacks that is completely resilient to network jitter. This means that remote timing attacks can now be executed with a performance and accuracy that is similar as if the attack was performed on the local system. With this technique, which leverages coalescing of network packets and request multiplexing, it is possible to detect timing differences as small as 100ns over any Internet connection. We will elaborate on how this technique can be launched against HTTP/2 webservers, Tor onion services, and EAP-pwd, a popular Wi-Fi authentication method. REFERENCES: See page 15 to 17 in our paper for a list of references: https://www.usenix.org/system/files/sec20-van_goethem.pdf

Presenters:

• Mathy Vanhoef - Postdoctoral Researcher, NYU
  Mathy Vanhoef is a postdoctoral researcher at New York University Abu Dhabi. His research interest lies in computer security with a focus on network and wireless security (e.g. Wi-Fi), software security, and applied cryptography. In these areas Mathy tries to bridge the gap between real-world code and (protocol) standards. He previously discovered the KRACK attack against WPA2, the RC4 NOMORE attack against RC4, and the Dragonblood attack against WPA3. @vanhoefm
• Tom Van Goethem - Researcher, KU Leuven
  Tom Van Goethem is a researcher with the DistriNet group at KU Leuven in Belgium, mainly focusing on practical side-channel attacks against web applications and browsers. By exposing flaws that result from the unintended interplay of different components or network layers, Tom aims to bring us closer to a more secure web that we all deserve. He has spoken at various venues such as Black Hat USA and Asia, OWASP Global, and USENIX Security. In his spare time, Tom provides animal sculptures with pink tutus. @tomvangoethem

Links:

• https://defcon.org/html/defcon-29/dc-29-speakers.html#van_goethem
• https://infocon.org/cons/DEF CON/DEF CON 29/DEF CON 29 video and slides/DEF CON 29 - Tom Van Goethem Mathy Vanhoef - Timeless Timing Attacks.mp4
• https://infocon.org/cons/DEF CON/DEF CON 29/DEF CON 29 presentations/Tom Van Goethem Mathy Vanhoef - Timeless Timing Attacks.pdf (slides)
• https://infocon.org/cons/DEF CON/DEF CON 29/DEF CON 29 video and slides/DEF CON 29 - Tom Van Goethem Mathy Vanhoef - Timeless Timing Attacks.srt (subtitles)
• https://www.youtube.com/watch?v=s5w4RG7-Y6g

Similar Presentations:

• Black Hat USA 2015 / Web Timing Attacks Made Practical
• DEF CON 15 (2007) / It's All About the Timing
• Black Hat USA 2021 / Timeless Timing Attacks