<!-- SPDX-License-Identifier: CC-BY-4.0 -->

# PrismShare protocol model

**Status:** Research draft 0<br>
**Published:** 2026-08-11<br>
**Licence:** CC BY 4.0

PrismShare is an open optical networking protocol research project built on
QR-compatible symbols. Its objective is to turn a sequence of visible symbols
into a persistent screen-to-camera link that can adapt, stream, recover from
loss, authenticate transmitting context, and carry multiple logical
applications.

This document is a capability and architecture model. It is not yet a stable,
interoperable wire specification.

## Design objective

A conventional QR exchange commonly yields one decoded payload. PrismShare
explores a longer-lived relationship:

```text
SCREEN
  -> QR-COMPATIBLE OPTICAL FRAMES
  -> CAMERA
  -> FRAME RECONSTRUCTION
  -> AUTHENTICATED SESSION CONTEXT
  -> MULTIPLEXED APPLICATION CHANNELS
```

The optical path should not require Wi-Fi, Bluetooth, NFC, a cable, removable
media, or an Internet connection. Receiving software still requires permission
to use its camera.

## Target capabilities

- **Adaptive:** adjust optical encoding and transmission behaviour as the
  receiver, camera, display, distance, and loss conditions change.
- **Streaming:** keep a link alive across a succession of symbols rather than
  treating each symbol as an unrelated payload.
- **Authenticated:** carry credentials, public keys, signatures, challenges,
  and rotating proofs continuously enough to establish a verifiable
  transmitting context.
- **Loss-tolerant:** use fragmentation, retransmission, and forward error
  correction so a receiver can reconstruct useful data despite missed frames.
- **Multiplexed:** carry multiple logical application channels over one
  persistent optical session.

## Layer model

```text
APPLICATIONS
  PrismDrop / PrismID / PrismLink / PrismVault / PrismMesh

MULTIPLEXED LOGICAL CHANNELS

ADDRESSING / DISCOVERY / ROUTING

IDENTITY / AUTHENTICATION / SESSION

FRAGMENTATION / RETRANSMISSION / FEC

QR-COMPATIBLE OPTICAL FRAMES

SCREEN <-> CAMERA
```

Addressing, discovery, identity, session management, fragmentation,
retransmission, forward error correction, logical-channel multiplexing, and
routing sit above the visible symbol format but remain part of the PrismShare
protocol system.

## Authentication boundary

PrismShare aims to let a receiver determine who is maintaining a transmitting
context, not only what bytes appeared in a square. The stream may carry
identity material and cryptographic proofs, but authentication is not the same
as trust or authorisation. Applications decide which identities, credentials,
proofs, and actions they accept.

An authenticated stream does not by itself provide confidentiality. An
application such as PrismLink can negotiate encryption after authenticating
the session context.

## Example applications

### PrismDrop — “AirDrop without the radio.”

Transfer files between devices using only screen and camera.

### PrismID — “Your identity can speak for itself.”

A continuously authenticated QR stream carrying cryptographic proofs and
selective credentials.

### PrismLink — “Point to connect.”

Establish an encrypted session simply by devices seeing each other.

### PrismVault — “Offline means offline.”

Move transactions into and out of permanently air-gapped systems without USB
drives or network interfaces.

### PrismMesh — “Carry the network with you.”

Devices exchange authenticated messages locally and physically carry
information between disconnected groups.

PrismLink and PrismDrop are the intended first demonstration path. PrismID and
PrismVault are the clearest differentiated uses. PrismMesh describes the
longer-term delay-tolerant network direction.

## Research status and non-claims

Existing MASHR experiments demonstrate narrower ingredients such as bounded
static and animated QR-compatible payloads, fountain reconstruction, signed
objects, and offline scanning. They do not constitute the complete PrismShare
protocol described here.

The current research does not publish a stable wire format, interoperability
profile, security proof, production encoder/decoder, browser camera
implementation, routing protocol, or completed application. The site’s optical
link is a visual simulation, not a live transfer.