COCRYPT
User guide
Start with your recovery phrase, then agree who will participate. Keep a copy of the encrypted .cvl file and protect each participant’s 12 words separately. Beyondend cannot recover lost keys; a missing key without its recovery phrase can leave the file inaccessible.
1. Prepare your key
Choose Create New Key, securely record the 12 words, and finish setup. To recover an existing key, choose Restore and enter the original phrase.
2. Choose the participants
The owner opens Lock My File. Each participant chooses Send Participant Key, authenticates and brings their phone nearby. The owner collects each public key and reviews the list before continuing.
3. Lock and save
Select the source file. CoCrypt creates its encrypted .cvl container. Use Save to keep or share it before choosing Clean and Close, which deletes the generated output from the app.
4. Collect approvals and unlock
Open the .cvl file and request approval from each remaining participant. They choose Approve, authenticate and bring their device nearby. Approvals are collected sequentially. Once every required piece is available, unlock and save the decrypted file.
Owner and participant roles
The owner’s own key is included by default and can be removed before encryption. If its matching key is on the unlocking device, that piece is recovered locally. Collective control depends on the participant list you select.
After unlocking
The decrypted output is an ordinary file. CoCrypt does not control copies saved or shared outside the app. Leaving with Back does not delete the generated output; use Clean and Close after saving what you need.
Every key piece counts
AES-256-GCM protects the file. Its key is split into N pieces with XOR; all pieces are required to reconstruct it. Each piece is encrypted for its participant using EC P-256 and ECIES.
Nearby, device to device
Exchange public keys and collect approvals over Bluetooth Low Energy. Encryption and approval need no internet connection or cloud relay.
Approve with biometrics
Participants authenticate with face or fingerprint recognition on their own device before sending an approval. CoCrypt receives the authentication result, not biometric templates.
A fresh challenge
Unlock requests use a fresh, time-stamped challenge. The app verifies the participant’s ECDSA signature before accepting the returned key piece.
Your key, your recovery
Create a 12-word recovery phrase during setup. It can restore the same key on another device. Keep it private: anyone with those words can recreate your key.
One portable .cvl file
Documents, images, videos and archives can be encrypted into a .cvl container. Save or share the encrypted file using the system share sheet. Device memory and storage limit file size.