Numinex
Notes on an experimental, multiplayer, open-world AI chat system built on the AT Protocol.
Henry de Valence
Latest posts
Stepping down from Penumbra Labs
Announcing my departure from Penumbra.
Gradual Dutch Auctions on Penumbra
Penumbra introduces protocol-level Dutch auctions for price discovery of new assets and better execution of trades, enabling gradual, privacy-preserving market matching.
Shielded Staking on Penumbra
Penumbra introduces private proof-of-stake using validator-specific delegation tokens, enabling private staking while maintaining validator accountability.
Shielded Upgradability
Penumbra Testnet 64 'Titan' introduces support for shielded chain upgrades, enabling network coordination on software versions while preserving private user data across upgrades.
Bringing Shielded Transactions to the Web
Penumbra Testnet 63 introduces a web wallet and frontend enabling private transactions in the browser without compromising security.
Interchain Privacy Is Here
Penumbra's testnet now supports IBC and ICS-20 token transfers, bringing privacy to the Interchain through decentralized, permissionless token transfers from any IBC-compatible chain into Penumbra's multi-asset shielded pool.
Penumbra's DEX Arrives From The Future
Penumbra testnet launches a private, concentrated-liquidity DEX with batched execution, optimal routing, and in-protocol arbitrage - advancing DEX capabilities beyond current systems.
Penumbra Winter 2022 Update
Major progress on shielded swaps, transaction plans, state models, client sync, governance MVP, and ZK proofs. Plus roadmap for DEX engine and web interfaces.
Penumbra Testnet 38: Kalyke
Major improvements simplify client development with tokenized unbonding, personal rollups, and simplified swaps, making Penumbra's privacy features easier to implement.
Penumbra Testnet 29: Shielded Swaps Have Arrived
Penumbra's 29th testnet release introduces private token swaps within the shielded pool, using batch processing to minimize MEV and eliminate transaction ordering.
Penumbra Summer 2022 Update
Major progress on core infrastructure including Decaf377 cryptography, Jellyfish Merkle Tree implementation, private staking, and the first non-SDK IBC connection to Cosmos Hub.
Testnet #4: Shielded Staking Is Here
Penumbra's fourth testnet, Thelxinoë, introduces private staking and delegation mechanics using delegation tokens, enabling privacy for delegators while maintaining validator accountability.
Public Testnet #1: "Valetudo"
Penumbra launches its first public testnet featuring multi-asset shielded transactions and client-side chain scanning, marking a key milestone in private blockchain design.
How We're Building Penumbra
An overview of Penumbra's development approach to building a fully shielded proof-of-stake blockchain, using transparent proofs to iterate on privacy-preserving mechanics.
Penumbra Labs Raises Seed Round To Build Private, Decentralized Exchange
Announcing my startup, Penumbra Labs, and its $4.75M seed round led by Dragonfly Capital, with the goal of bringing privacy to DeFi.
It's 255:19AM. Do you know what your validation criteria are?
Ed25519 signature validation criteria vary widely between implementations, creating risks for consensus systems. Here's why and how to fix it.
Private Contact Tracing Protocols Compared: DP-3T and CEN
Two leading privacy-preserving contact tracing protocols, DP-3T and CEN, show similar approaches. Here's how they compare on privacy & security. (Both were subsumed by the Apple/Google Exposure Notification protocol.)
Design Tradeoffs in Privacy-Preserving Contact Tracing
As we build privacy-preserving contact tracing, let's examine key tradeoffs: trust, privacy, and health authority dependence. Here's what we've learned.
Let's Develop Decentralized, Privacy-Preserving Contact Tracing
A call to action in the early stages of the COVID-19 pandemic, urging grassroots action to respond to institutional failure.
Decoding Bitcoin Messages with Tokio Codecs
How Zebra uses Tokio's codec functionality to efficiently parse Bitcoin wire protocol messages into typed data structures for Zcash nodes.
Composable Futures-based Batch Verification
A novel approach to batch verification of cryptographic data, using futures to disentangle validation states and transparently batch verification checks.
A New Network Stack For Zcash
The first step towards a second, interoperable Zcash implementation: a modernized networking stack built with async Rust and Tokio.
zkp: a toolkit for Schnorr proofs
A Rust library providing high-level macros and low-level APIs for generating and verifying Schnorr-style discrete logarithm proofs with optimized performance
Flexible precomputation for verification checks
New API in curve25519-dalek v1.1 enables partial precomputation for multiscalar multiplication, yielding 20-30% speedup across a wide range of protocols.
Even faster Edwards curves with IFMA
Further speed records for elliptic curve operations, using Intel's AVX512-IFMA instructions to implement parallel Edwards curve formulas.
Bulletproofs pre-release
Announcing the stable pre-release version of Bulletproofs, with type-safe multiparty computation, further optimizations, and support for generic circuit-based proof statements.
Merlin: flexible, composable transcripts for zero-knowledge proofs
Automatic Fiat-Shamir transformations for complex zero-knowledge proofs, with flexible domain separation, multi-round protocols, automatic message framing, and composition of proof statements.
Accelerating Edwards Curve Arithmetic with Parallel Formulas
New speed records for elliptic curve operations by implementing parallel Edwards curve formulas with SIMD/AVX2 vectorization.
Faster Bulletproofs with Ristretto and AVX2
Implementation of Bulletproofs range proofs using Ristretto & AVX2 optimizations in Rust, achieving 1.15ms verification for 64-bit proofs.
SIDH in Go for quantum-resistant TLS 1.3
During a summer internship at Cloudflare, I designed and implemented quantum-resistant TLS 1.3 in Go using supersingular isogeny Diffie-Hellman.
When ‘he’ll be kept on payroll, somewhere’ is where you are
The story of why I quit my cryptography PhD
Capitalism and Arithmetic and Casting Out Nines
Exploring the historical Treviso Arithmetic from 1478 and its method of 'casting out nines' for error checking in arithmetic calculations.
Fun with n-grams, part 2: tightly packed tries
Exploring tightly packed tries as a space-efficient data structure for storing n-grams, using information theory and clever encoding techniques.
Fun with Google n-grams data (part 1)
Exploring data structure optimizations for working with Google's massive n-gram datasets, including tries and tagged pointers.
Converting KML files to shapefiles with extra data
A guide on converting KML files with ExtendedData tags to shapefiles using GDAL's ogr2ogr tool, including tips on enabling LibKML support in Arch Linux for proper data conversion.
Better Living Through Clang-istry
Exploring how to use Clang's memory layout dump feature to optimize C++ object sizes, resulting in a 10% memory reduction by eliminating padding and reconsidering data types.
Notes on my Arch Linux install
Personal notes on installing Arch Linux with bcache, btrfs, and radeon drivers - including important caveats about bcache/btrfs compatibility
Haskell, Lasers, and Curved-Fold Origami
Using a laser cutter and Haskell to create precise curved-fold origami patterns, with concentric circles scored on both sides of the paper
KStars GSoC: OpenCL and a first performance report
Implementing optional OpenCL support in KStars and benchmarking the new algorithms, showing 56x speedup from better algorithms and 132x with OpenCL
KStars GSoC: Aberration with a Stereographic Projection
Using stereographic projection to simplify stellar aberration calculations in KStars, replacing complex trigonometry with elegant geometric transformations
KStars GSoC: Progress Update
Progress report on rewriting KStars' coordinate transformations using linear algebra instead of spherical trigonometry for better performance
Intel VTune on Linux 3.9 workaround for hlist_for_each_entry
How to fix Intel VTune's sepdk driver compilation errors on Linux 3.9+ by adapting to kernel API changes in hlist iterators
Quaternions and Rotations
An exploration of how quaternions provide an elegant way to represent 3D rotations, avoiding the problems of Euler angles and matrices
Coordinate Systems in KStars
An overview of astronomical coordinate systems used in KStars - horizontal, equatorial, ecliptic, and galactic - and how to convert between them
KStars Summer of Code 2013
Introducing my Google Summer of Code project to rewrite KStars' astronomy engine using OpenCL for better performance
Lord Macaulay on copyright
A historic speech from 1842 where Macaulay argues against extending copyright terms, using examples from Wesley, Shakespeare, and Austen
JPEG compression and retina displays
Investigating the quality/size tradeoffs of JPEG compression at different resolutions for high-DPI displays
QOTD: Newton on Cassegrain
A quote from Isaac Newton about Cassegrain's telescope design
A portable photocopier with OpenCV
Building a Python script using OpenCV to transform photos of documents into clean, flat, high-contrast scans