# Solid(ar)ity

> A decentralized identity wallet that generates zero-knowledge proofs and exchanges signed cards face to face.

Canonical: https://solidarity.gg/

Solid(ar)ity is a decentralized identity wallet for iPhone and Android. It generates zero-knowledge proofs on your phone and exchanges cryptographically signed cards face to face, so you can prove who you are without revealing who you are. No account, no login screen, no central server holding your identity.

## Key facts

- Category: decentralized identity wallet and privacy-first business card app.
- Platforms: iPhone (App Store) and Android (Google Play). Free to download.
- Store listing name: "Solid(ar)ity - P2P Connection".
- Identity: a self-sovereign DID created on your device and guarded by your phone's biometrics. No vendor account, no recovery email.
- Proofs: zero-knowledge proofs of attributes (for example, over 18) and group membership, generated on the phone. A passport's NFC chip can back personhood and age claims; the passport data stays on the device.
- Exchange: cards are cryptographically signed by the sender's key and shared face to face via QR, Bluetooth, or AirDrop, with per-field selective disclosure.
- Standards: W3C Verifiable Credentials, Decentralized Identifiers (DIDs), OID4VP, OID4VCI, and Semaphore group proofs.
- Works offline. Source code is open on GitHub.
- Solid(ar)ity is not a social network, a messaging platform, a crypto token, or a media hosting service.

## Download

- [App Store (iPhone)](https://apps.apple.com/app/solid-ar-ity/id6752410250)
- [Google Play (Android)](https://play.google.com/store/apps/details?id=gg.solidarity.app)

## Why it exists

### Revolution begins at the periphery

Privacy is not a feature. Privacy is hygiene. An identity system that doesn't enforce privacy at the base layer is a surveillance tool with a friendlier interface.

### We stand against singular top-down mechanisms and the Pursuit of Global Consensus

You shouldn't have to register with an authority to own a digital identity. Your phone is enough. The person in front of you is enough.

### Designed for Real Life

Works offline. Works without permission. Works without a login screen. Each piece composes with the rest, so communities grow on their own terms, not a platform's.

## Principles

- Privacy-First
- Extensible
- Zero Infrastructure
- Self-Sovereign
- Open Standards
- Zero-Install Verification

## Building blocks of digital trust

Six pieces. Each works alone. All compose together. Identity, contacts, and proofs stay on your device, on your terms.

### Contact Graph

Every card you receive is signed with the sender's key. A verifiable edge in your social graph, one face-to-face encounter at a time.

### Identity

A self-sovereign DID, guarded by Face ID. You create it, you present it, you rotate it. No vendor, no gatekeeper, no recovery email.

### Proximity

Discovery over Bluetooth, QR, and AirDrop. No server in between, no login screen first. The person in front of you is the network.

### Ichigo-Ichie

A 140-character note from both sides, at the moment you met. Not a chat. Not a feed. A digital memento of that day, that place, that encounter.

### Selective Disclosure

Per-field control over what every person sees. Share only what matters for this encounter. The passport stays in your pocket.

### ZK Proofs

Group membership and attribute claims via zero-knowledge proofs. Prove you belong, prove you are over 18, prove anything true while revealing nothing else.

## FAQ

### What is Solid(ar)ity?

Solid(ar)ity is a decentralized identity wallet for iPhone and Android. It generates zero-knowledge proofs on your phone and exchanges cryptographically signed cards face to face, so you can prove who you are without revealing who you are.

### How can I prove something about myself without revealing who I am?

Solid(ar)ity generates a zero-knowledge proof on your phone for one specific claim, such as being over 18 or belonging to a group. The other person learns that the claim is true and nothing else: not your name, your passport number, or your birthday.

### Do I need an account or a server to use Solid(ar)ity?

No. There is no account, no login screen, and no recovery email. Your identity is a self-sovereign DID created on your device and guarded by your phone's biometrics, and cards are exchanged directly between phones.

### What happens when two people exchange cards?

Each card is signed with the sender's key, so the receiver can verify who sent it. You choose per field what the other person sees, and you can add a 140-character note that marks the moment you met.

### Which standards does Solid(ar)ity use?

Solid(ar)ity builds on W3C Verifiable Credentials, Decentralized Identifiers (DIDs), OID4VP and OID4VCI, with Semaphore for zero-knowledge group membership proofs.

### Is Solid(ar)ity free, and where can I get it?

Solid(ar)ity is free to download on the App Store for iPhone and on Google Play for Android. The source code is open on GitHub.

## Links

- [Documentation](https://docs.solidarity.gg)
- [Source code](https://github.com/p2p-solidarity/solidarity)
- [Support](https://solidarity.gg/support): gm@solidarity.gg
- [Privacy Policy](https://solidarity.gg/privacy)
- [Child Safety Standards](https://solidarity.gg/csae)
- [X / Twitter](https://twitter.com/p2p_solidarity)