# CoCrypt — Multi Bio Proximity Encryption

> Multi Bio Proximity Encryption (iPhone/iPad app by Erhan Olgunelma.)

- Source: https://appshunter.io/ios/app/cocrypt/id6759932131 (this page in markdown: same URL + `.md`)
- Developer: [Erhan Olgunelma](https://appshunter.io/developer/1771667365)
- Category: Utilities
- Price: Free (on sale, was $4.99)
- Age rating: 17+
- Requires: iOS 16.0 · 24 MB
- Languages: American English
- Released: 2026-05-29
- Data updated: 2026-07-22
- User reviews in markdown: https://appshunter.io/ios/app/cocrypt/id6759932131/reviews.md

## What is CoCrypt?

CoCrypt protects your files with collective encryption — a file can only be unlocked when every trusted participant is physically present and confirms in person. No exceptions.

How It Works
1. Key Registration: Each participant generates a unique cryptographic key pair on their own device. Public keys are exchanged wirelessly through physical proximity — nothing leaves the room.
2. Locking: The owner encrypts any file. The encryption key is mathematically split into fragments, one per participant, and sealed into a single .cvl file.
3. Collective Unlocking: Every participant must physically bring their device close to unlock. A single missing presence makes decryption mathematically impossible — forever.

Key Features
- N-of-N Collective Approval: Ownership is truly shared. Not one person, not a majority — everyone must be present.
- Presence-Based Key Exchange: Keys are exchanged through physical proximity only. No internet, no cloud, no remote access.
- Challenge-Response Protocol: Every session uses a unique time-stamped ECDSA challenge, making replay attacks impossible.
- Zero-Cloud & Zero-Account: No servers. No accounts. No telemetry. Private keys never leave the device's secure hardware.
- Universal File Support: Documents, photos, videos, archives — any file format can be locked.

Ideal For
- Enterprises: Require all board members to be physically present before accessing critical files.
- Families: Protect inheritance documents, accessible only when the whole family is together.
- Teams: Store shared secrets where no single individual holds complete authority.
- Journalists: Tie source access to the physical authorization of multiple colleagues.


## Version history (last 1 release)

### 1.0 — 2026-05-29

No release notes.

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-22.*