Introducing constant-time support for LLVM to protect cryptographic codeTrail of Bits developed constant-time coding support for LLVM that prevents compilers from breaking cryptographic implementations vulnerable to timing attacks, introducing the __builtin_ct_select family of intrinsics that preserve constant-time properties throughout compilation.
We found cryptography bugs in the elliptic library using WycheproofTrail of Bits discovered and disclosed two vulnerabilities in the widely used elliptic JavaScript library that could allow signature forgery or prevent valid signature verification, with one vulnerability still unfixed after the 90-day disclosure window.
How we avoided side-channels in our new post-quantum Go cryptography librariesWe’ve released open-source Go implementations of ML-DSA and SLH-DSA.
The cryptography behind electronic passportsThis blog post describes how electronic passports work, the threats within their threat model, and how they protect against those threats using cryptography. It also discusses the implications of using electronic passports for novel applications, such as zero-knowledge identity proofs.
Vulnerabilities in LUKS2 disk encryption for confidential VMsTrail of Bits is disclosing vulnerabilities in confidential computing systems that use LUKS2 for disk encryption. These vulnerabilities allow attackers with access to storage disks to extract confidential data and modify contents.
Building secure messaging is hard: A nuanced take on the Bitchat security debateThe release of Bitchat last week was met with a mixture of glowing praise and sharp criticism. Both extremes bear some truth, but they also miss the mark and reveal gaps in how we discuss security in emerging products.
What we learned reviewing one of the first DKLs23 libraries from Silence LaboratoriesIn October 2023, we audited Silence Laboratories’ DKLs23 threshold signature scheme (TSS) library—one of the first production implementations of this then-novel protocol that uses oblivious transfer (OT) instead of traditional Paillier cryptography. Our review uncovered serious flaws that could enable key destruction attacks, which Silence Laboratories promptly fixed.
A deep dive into Axiom’s Halo2 circuitsOver two audits in 2023, we reviewed a blockchain system developed by Axiom that allows computing over the entire history of Ethereum, all verified by zero-knowledge proofs (ZKPs) on-chain using ZK-verified elliptic curve and SNARK recursion operations. This system is built using the Halo2 framework—a complex, emerging technology that presents many challenges when building a secure application, including potential under-constrained issues resulting from its low-level API.
The cryptography behind passkeysThis post will examine the cryptography behind passkeys, the guarantees they do or do not give, and interesting cryptographic things you can do with them, such as generating cryptographic keys and storing certificates.
Sneak peek: A new ASN.1 API for PythonWe’re working on integrating an ASN.1 API into PyCA Cryptography,built on top of the same Rust ASN.1 implementation already used byCryptography’s X.509 APIs.
Best practices for key derivationKey derivation is essential in many cryptographic applications, including key exchange, key management, secure communications, and building robust cryptographic primitives. But it’s also easy to get wrong: although standard tools exist for different key derivation needs, our audits often uncover improper uses of these tools that could compromise key security. Flickr’s API […]
Celebrating our 2024 open-source contributionsWhile Trail of Bits is known for developing security tools like Slither, Medusa, and Fickling, our engineering efforts extend far beyond our own projects. Throughout 2024, our team has been deeply engaged with the broader security ecosystem, tackling challenges in open-source tools and infrastructure that security engineers rely on every day. This year, our engineers […]
Friends don’t let friends reuse IVsIf you’ve encountered cryptography software, you’ve probably heard the advice to never use an IV twice—in fact, that’s exactly where the other common name, nonce (number used once), comes from. Depending on the cryptography involved, a reused nonce can reveal encrypted messages, or even leak your secret key! But common knowledge may not cover every […]
“YOLO” is not a valid hash constructionAmong the cryptographic missteps we see at Trail of Bits, “let’s build our own tool out of a hash function” is one of the most common. Clients have a problem along the lines of “we need to hash a bunch of different values together” or “we need a MAC” or “we need […]
We wrote the code, and the code wonEarlier this week, NIST officially announced three standards specifying FIPS-approved algorithms for post-quantum cryptography. The Stateless Hash-Based Digital Signature Algorithm (SLH-DSA) is one of these standardized algorithms. The Trail of Bits cryptography team has been anticipating this announcement, and we are excited to share an announcement of our own: we built an open-source pure-Rust implementation of SLH-DSA, which has been merged into RustCrypto.
Cloud cryptography demystified: Google Cloud PlatformThis post, the second in our series on cryptography in the cloud, provides an overview of the cloud cryptography services offered within Google Cloud Platform (GCP): when to use them, when not to use them, and important usage considerations. Stay tuned for future posts covering other cloud services. At Trail of Bits, […]
Our crypto experts answer 10 key questionsCryptography is a fundamental part of electronics and the internet that helps secure credit cards, cell phones, web browsing (fingers crossed you’re using TLS!), and even top-secret military data. Cryptography is just as essential in the blockchain space, with blockchains like Ethereum depending on hashes, Merkle trees, and ECDSA signatures, among other […]
Announcing AES-GEM (AES with Galois Extended Mode)Today, AES-GCM is one of two cipher modes used by TLS 1.3 (the other being ChaCha20-Poly1305) and the preferred method for encrypting data in FIPS-validated modules. But despite its overwhelming success, AES-GCM has been the root cause of some catastrophic failures: for example, Hanno Böck and Sean Devlin exploited nonce misuse to […]
Quantum is unimportant to post-quantumYou might be hearing a lot about post-quantum (PQ) cryptography lately, and it’s easy to wonder why it’s such a big deal when nobody has actually seen a quantum computer. But even if a quantum computer is never built, new PQ standards are safer, more resilient, and more flexible than their classical […]
Disarming Fiat-Shamir footgunsThe Fiat-Shamir transform is an important building block in zero-knowledge proofs (ZKPs) and multi-party computation (MPC). It allows zero-knowledge proofs based on interactive protocols to be made non-interactive. Essentially, it turns conversations into documents. This ability is at the core of powerful technologies like SNARKs and STARKs. Useful stuff! But the Fiat-Shamir […]
Themes from Real World Crypto 2024In March, Trail of Bits engineers traveled to the vibrant (and only slightly chilly) city of Toronto to attend Real World Crypto 2024, a three-day event that hosted hundreds of brilliant minds in the field of cryptography. We also attended three associated events: the Real World Post-Quantum Cryptography (RWPQC) workshop, the Fully Homomorphic Encryption (FHE) […]
A peek into build provenance for HomebrewLast November, we announced our collaboration with Alpha-Omega and OpenSSF to add build provenance to Homebrew. Today, we are pleased to announce that the core of that work is live and in public beta: homebrew-core is now cryptographically attesting to all bottles built in the official Homebrew CI. You […]
Announcing two new LMS librariesThe Trail of Bits cryptography team is pleased to announce the open-sourcing of our pure Rust and Go implementations of Leighton-Micali Hash-Based Signatures (LMS), a well-studied NIST-standardized post-quantum digital signature algorithm. If you or your organization are looking to transition to post-quantum support for digital signatures, both of these implementations have been […]
Cryptographic design review of OckamIn October 2023, Ockam hired Trail of Bits to review the design of its product, a set of protocols that aims to enable secure communication (i.e., end-to-end encrypted and mutually authenticated channels) across various heterogeneous networks. A secure system starts at the design […]
Circomspect has been integrated into the Sindri CLIOur tool Circomspect is now integrated into the Sindri command-line interface (CLI)! We designed Circomspect to help developers build Circom circuits more securely, particularly given the limited tooling support available for this novel programming framework. Integrating this tool into a development environment like that provided by Sindri is a significant step toward […]
