Quantum Computers Are Not a Threat to 128-bit Symmetric Keys

The advancing threat of cryptographically-relevant quantum computers has made it urgent to replace currently-deployed asymmetric cryptography primitives—key exchange ECDH and digital signatures RSA, ECDSA, EdDSA—which are vulnerable to Shor’s quantum algorithm. It does not, however, impact existi...

Cross-Site Request Forgery

Cross-Site Request Forgery CSRF is a confused deputy attack where the attacker causes the browser to send a request to a target using the ambient authority of the user’s cookies or network position.1 For example, attacker.example can serve the following HTML to a victim and the browser will send ...

Accumulated Test Vectors

I like tests. I especially like reusable test vector libraries. Sometimes test vectors are lovingly handcrafted to target obscure edge-cases. Those vectors belong in Wycheproof or with the upstream specification. Sometimes though vectors are produced by sheer brute force. Enumerate every possible...

A Retrospective Survey of 2024/2025 Open Source Supply Chain Compromises

Lack of memory safety is such a predominant cause of security issues that we have a responsibility as professional software engineering to robustly mitigate it in security-sensitive use cases—by using memory safe languages. Similarly, I have the growing impression that software supply chain...

The FIPS Compliance of HKDF

HKDF is an HMAC-based key-derivation function specified in RFC 5869. It’s nice and we generally like using it. FIPS Federal Information Processing Standards is used generally as a moniker for the set of standards, recommendations, and guidance published by the U.S. National Institute of Standards...

go.sum Is Not a Lockfile

I need everyone to stop looking at go.sum, especially to analyze dependency graphs. It is not a “lockfile,”1 and it has zero semantic effects on version resolution. There is truly no use case for ever parsing it outside of cmd/go. go.sum is only a local cache for the Go Checksum Database. It’s a...

Building a Transparent Keyserver

Today, we are going to build a keyserver to lookup age public keys. That part is boring. What’s interesting is that we’ll apply the same transparency log technology as the Go Checksum Database to keep the keyserver operator honest and unable to surreptitiously inject malicious keys, while still...

Opaque, Interoperable Passkey Records (and a Go API)

Passkeys are the most important thing happening in information security right now because they are the only principled solution to the overwhelming effectiveness of phishing attacks. Just like memory safety is the only principled solution to memory corruption attacks. Unfortunately, implementing...