Machine Learning 104: Breaking AES With Power Side-Channels
This executable blog post is the fourth in a series related to machine learning and is a fascinating trifecta involving hardened cryptography software, embedded IoT-type hardware, and deep machine learning techniques. While the AES algorithm is designed such that a brute-force secret key guessing attack would likely finish ‘sometime near eternity’, the power side-channel attack […]
Rigging the Vote: Uniqueness in Verifiable Random Functions
This blog post presents a whirlwind overview of Verifiable Random Functions (VRFs) as used by several leading-edge blockchains, and shows how a very interesting and recently found implementation oversight causes the VRF’s assurance of uniqueness to fall apart. As VRFs are commonly used for selecting blockchain consensus voting committees, this can result in a rigged […]
State of DNS Rebinding in 2023
Different forms of DNS rebinding attacks have been described as far back as 1996 for Java Applets and 2002 for JavaScript (Quick-Swap). It has been four years since our State of DNS Rebinding presentation in 2019 at DEF CON 27 (slides), where we introduced our DNS rebinding attack framework Singularity of Origin. In 2020, we […]
Machine Learning 103: Exploring LLM Code Generation
This executable blog post is the third in a series related to machine learning and explores code generation from a 16 billion parameter large language model (LLM). After a brief look under the hood at the LLM structure and parameter allocation, we generate a variety of Python functions and make observations related to code quality […]
Machine Learning 101: The Integrity of Image (Mis)Classification?
Professor Ron Rivest observed the close relationship between cryptography and machine learning at the ASIACRYPT conference back in 1991. Cross-fertilization of common notions, such as integrity, privacy, confidentiality and authenticity, have only grown in the following three decades as these fields have become more central to our everyday lives. This blog post is the first in […]
Curve9767 and Fast Signature Verification
This post is about elliptic curves as they are used in cryptography, in particular for signatures. There are many ways to define specific elliptic curves that strive to offer a good balance between security and performance; here, I am talking about specific contributions of mine: a new curve definition, and some algorithmic improvements that target […]
The Extended AWS Security Ramp-Up Guide
On November 25th, AWS released the Ramp-Up Learning Guide for AWS Cloud Security, Governance, and Compliance. The Security Ramp-Up is a curated list of educational AWS resources. The goal is “to teach in-demand cloud skills and real-world knowledge that you can rely on to keep up with cloud security, governance, and compliance developments and grow […]
Code Patterns for API Authorization: Designing for Security
Summary This post describes some of the most common design patterns for authorization checking in web application code. Comparisons are made between the design patterns to help understand when each pattern makes sense as well as the drawbacks of the pattern. For developers and architects, this post helps you to understand what the different code […]
How cryptography is used to monitor the spread of COVID-19
On April 10, Apple and Google announced1, 2 that they were joining forces in an effort to help reduce the spread of COVID-19. Their solution leverages Bluetooth technology to trace interactions between individuals. This principle is known as contact tracing and public health agencies are heavily relying on it to monitor and prevent the spread […]
C Language Standards Update – Zero-size Reallocations are Undefined Behavior
[Editor’s Note: Robert Seacord of NCC Group is a longstanding member of the C Standards Committee. In this blog post, he outlines a recently adopted change he proposed to the C Language Standard, to help eliminate double-free vulnerabilities being introduced to C code as a result of zero-sized reallocations of memory.] by Robert Seacord The […]