The Post-Quantum Field Guide
A working post-quantum cryptographer’s guide to the quantum transition: what’s coming for the cryptography the whole world runs on, why it matters, and what to actually do about it.
Start here
Pick the line that sounds like you, and I’ll walk you through it in the right order.
New to all of this? Start with Why This Exists, then pick a door below.
- You want to understand the whole thing, start to finish. → Start at the beginning, then follow the journey below.
- You just need one specific standard or term. → Search, or open any note directly. Each one is a self-contained, cited answer.
- You want the arguments rather than the reference. → Analysis indexes every note in this Guide that defends a claim, from why migrations stall to what the skeptics get right.
Each of the first 4 doors is a guided path: a sequence of steps that routes you through exactly the notes you need, in the order that makes them click. The last 2 open Quantum Risk, in Plain English, which carries the same facts and citations as the technical notes with only the language changed, including 4 self-contained briefs for reporters at For Press.
What the transition is
The post-quantum transition is the global effort to replace the public-key cryptography protecting today’s digital infrastructure before quantum computers can break it. A large enough quantum computer running Shor’s algorithm would defeat RSA, Diffie-Hellman, and elliptic-curve cryptography, the algorithms behind secure web traffic, digital signatures, and encrypted data. NIST has published the replacement standards (ML-KEM, ML-DSA, and others), and organizations are now migrating to them on real regulatory deadlines.
Maintained by Addie LaMarr, a working cryptographer. Every load-bearing claim cited to its primary source. Last verified 2 August 2026.
How to use this Guide
- Hover over any linked term and its note pops up, the definition and full page, without you leaving the one you’re on.
- The left sidebar is a complete index of every note. Browse it freely.
- MOCs (Maps of Content) are the section hubs. Each one indexes its topic and routes you through it in order.
- The Table of Contents, on the right, lists every heading in the note, so you can jump straight to any section.
- Backlinks, on the right under the Table of Contents, show what else references this note, so you can see what connects to what.
- The graph panel shows the notes linked to the one you’re reading. Treat it as a map, not a menu: following the links inside a note is easier to navigate than clicking around the graph.
The journey
The complete arc, walkable from zero. Each section builds on the one before it.
The three dimensions
The transition runs on three dimensions at once, technical, organizational, and human, and it stalls on the last two. This Guide maps all three.
- Technical: the cryptography, the standards, the architecture.
- Organizational: where the transition really stalls: the algorithm hidden in dozens of unmapped vendor products, who owns what, governance as an operating model.
- Human: the change nobody plans for: people fear their skills are obsolete and resist, so the work is bringing them along, three small reversible moves at a time.
Who’s behind this, and why listen
I’m Addie LaMarr, and I’ve spent 15 years inside the cryptography the whole world runs on: 8 as an applied cryptographer in the U.S. Air Force, then writing federal policy and advising CISOs at the FBI and the Department of Justice. I’ve worked both ends of this transition, the hands on the key-management infrastructure and the pen on the governance memo, which is why I can see where these programs actually break. Today I run LaMarr Labs, an independent post-quantum cryptography consultancy.
I also read the quantum shift differently from most of the field. It’s a cryptography story with 2,500 years of precedent behind it, and I’ve spent my life obsessed with that history, from Bletchley Park to the Navajo code talkers to the Zimmermann Telegram. That lineage is the most honest teacher we have for what’s coming, and it’s what makes this whole thing finally click.
I built this guide to be the map I wish someone had handed me: honest, complete, cited, and free. The fuller story is on the About Addie page. When your team wants this quantified against your own estate and defensible to your regulator, that’s the work I’m brought in to do. Request a briefing.
Checked, cited, and free
Every concept note opens with a plain-English summary, carries its citations inline, and shows the date it was last verified against the primary source. The deep reference graph underneath the journey is where the detail lives, and it’s all free.
Two things about how that verification is enforced, because “we cite our sources” is a claim anyone can make.
- A note is checked against the source document, not against reporting about it. Where an arXiv abstract page and the paper’s own PDF disagreed on a figure, which has happened here, neither number is used and the detail is dropped until the source is unambiguous.
- Superseded figures are added beside the current ones, never quietly swapped, and a script enforces it across the whole corpus. When a widely quoted number is overtaken, the older peer-reviewed anchor stays next to the newer result, partly so a reader sees the trend and partly because downstream numbers often derive from the older paper’s formula. A corpus-wide check fails any note that quotes a legacy figure without stating the current one alongside it, which catches the one defect a per-page review structurally cannot see: a page that is internally consistent, correctly cited, and 4 months out of date.
If the guide helps you along the way, I’d love to hear about it. That’s the only thing I ever ask for the map.