You're viewing the readable version of this site. The interactive extras (search, diagrams, read-aloud) need JavaScript and a current browser. Enable JavaScript; if it is already enabled, update your browser.

Internal · Testbed

evergreen

Bounded Nonces, Live

A layout testbed for the talk page type — the presented form of the research-paper specimen: venue block, slides as headings, stage text, stepped viz islands, speaker-note prose, and the delivered-at evidence record.

·

testbed, typography, talk, design-system, internal

A talk is a paper performed. The figures should live twice as hard on stage as they do on the page.

— Ada R. Cipher, Colloquium notes (2026)

This page is a fixture, not a lecture: it exercises every element of the talk layout (design: docs/design/features/talk.md) the way the kitchen sink exercises the article and _research-paper exercises the paper. It presents the same fictional result as the paper specimen — the sufficiency of bounded nonces — because a specimen family should tell one story across layouts. In scroll form (what you are reading, the no-JS canonical form) each top-level heading is a slide, and the prose under it is simultaneously the transcript and the speaker notes. In stage form only the slidetext blocks and the figures render, one slide per screen; arrow keys (or clicking the right of the screen, or the on-screen controls) advance beats, and a beat drives the slide's figures and uncovers the next point of a bulleted slidetext. Click the left third to go back. Clicking any slide sheet in this scroll form lifts it straight onto the stage.

Bounded Nonces, Live

Bounded Nonces, Live

The title sheet. :SLIDE_KIND: title in the heading's property drawer becomes data-slide_kind"title"= on the section (Pandoc, no filter): the heading label is dropped and the claim fills the sheet. On stage the brand mark (#+LOGO:) rides the folio; this is the opening frame.

The question is narrower than the folklore

How wide must a nonce be?

Speaker notes live here, as ordinary prose. On stage this paragraph does not render; in scroll form it is the transcript. The opening move of the talk: the folklore says "more random is more secure," and implementers pay for width they never measure. The narrow question — how wide is enough? — has a bound, a construction, and a measurement.

Margin notes work in the scroll projection exactly as in articles; the stage projection ignores them, the print handout keeps them.

One figure, four beats

The margin of safety is exponential in kk.

This slide exists to exercise a stepped island: the viz block below declares talk_steps, so on stage the presenter's four advances dispatch four messages into the island's machine — the figure moves, the text stands still. In scroll form the island renders as it would in any article: fully interactive, reader-driven.

The adversary's advantage as token width grows. On stage this figure is driven in four steps — k = 32, 64, 96, 128 — each advance an event into the same machine a reader can drive by hand in the scroll form.

Part II · The construction

A section divider: :SLIDE_KIND: section turns the heading itself into the stage — no boxed sheet, just the part title set large and centered. In scroll form it reads as a chapter break in the transcript. Dividers carry no beats; they are one advance each.

Three moves, revealed in turn

The whole protocol is three moves.

  • Generate kk bits from the world's CSPRNG.
  • Encode fixed-width (base64url) — no length leak.
  • Verify by constant-time equality. Nothing else.

This slide exercises progressive reveal: the slidetext carries a bulleted list, so on stage each advance uncovers the next point (the claim above shows from the first beat). In scroll form — the canonical document — the whole list is visible at once; the deck withholds nothing the reader can't already read. Reveal beats compose on the same axis as figure steps: a slide with both would advance them together.

The construction fits on a slide

Generate; encode; verify by equality. Nothing else.

A code block exercises the stage's monospace setting — it renders in both projections, and it must survive the stage's enlarged type scale without horizontal scroll on a 16:9 screen:

function nonce(world: World, k: 128): string {
  const bytes = world.randomBytes(k / 8); // CSPRNG or nothing
  return base64url(bytes);                // fixed-width encoding
}

A fixed-width nonce helper. The slide-scale code block must stay readable without horizontal scroll.

What the measurement said

1.6 million responses. Zero collisions. k=128k = 128 is comfortable.

This column carries a vertical deep dive (design: docs/design/features/talk.md §12). On stage, press ↓ to descend into the two sub-slides below; press ↑ to come back to this spine, or → to skip the dive and move on. In the scroll form the sub-slides read as indented subsections — the deep dive is never hidden from the transcript, only tucked below the fold on stage.

How the collisions were counted

Birthday bound: expected first collision near 2k/22^{k/2} draws.

A deep-dive row: the methodology a curious audience member might ask about. Its own slidetext is the terse claim; this prose is its notes.

Why 1.6 million is enough

1.6×1062641.6\times10^{6} \ll 2^{64} — the sample never approaches the bound.

The second row of the dive. Press → from here to leave the column and land on the next spine slide.

The results beat: a slide whose stage text is a single claim, whose notes carry the caveats. The caveats are the point of the notes — the stage form states, the scroll form argues. A blockquote exercises quotation styling in both projections:

The marginal security of additional bits falls off exponentially while the cost of generation stays constant.

Close: the handout is the paper

Read the paper. The slides were never the document.

The closing beat points at the paper specimen — in a real talk this is the "read more / cite this" slide, and the printed form of this very page is the Tufte handout. See the written form at the research-paper testbed.

Delivered at

This section is the evidence record the layout formalizes: venue, date, and recording for each performance of the talk, self-hosted and permanent. A real talk page accretes one row per delivery; the recording link enables the future watch mode (cue-synced playback).

  • Colloquium Series, Institute for Applied Marginalia — 4 July
    1. Recording: (placeholder — served same-origin when real).
    Slides: this page, stage form.