Nothing personal, just business

Core51 is a corporate messenger for day to day work: decisions, approvals, handoffs, and sensitive discussions. End to end encryption protects confidentiality by default: messages are encrypted on device and the server is treated as untrusted. Only participants can read the content. And if something goes off plan, conversations can be exported with verifiable proof suitable for arbitration, audits, and disputes.

Features

End-to-end encryption for all chats
Message as proof of a deal
Two export levels: pre-trial dispute resolution and court-grade forensics
No chat deletion (you can freeze a chat and move it to the Frozen Chats)
Custom chat names
Color labels for chats

Security

Designed for confidentiality and integrity

End to end encryption

Messages are encrypted on device. The server stores ciphertext and delivery metadata.

Key continuity

TOFU model: keys are pinned on first contact, and changes require explicit re trust.

Audit visibility

Security relevant events can be reviewed, including key changes and verification checks.

Arbitration and disputes

Sometimes you need a chat to serve as proof of a deal. Core51 supports two simple export models - choose the one that matches your situation.

Two export models

1) Decrypted text (for pre-trial actions)

This is the practical option when you need to act fast: a claim letter, negotiations, mediation, a notary, or other pre-trial steps.

What you share: readable message text (and timestamps / participants).
Why it is useful: people can read it immediately.
Important note: the recipient must trust the text was not edited.

2) Encrypted proof package (for court / forensic review)

You export an encrypted chat bundle. It stays encrypted until the account owner decides to reveal the private key. After the private key is provided, the bundle can be decrypted and checked.

What you share first: an encrypted export file.
When plaintext is revealed: only after the private key is provided.
Why it is useful: an expert can verify the decrypted transcript matches the exported package.

Which one should I use?

Use model 1 when

You need speed and readability: pre-trial letters, settlement talks, negotiation, or mediation.

Use model 2 when

You need maximum credibility and technical verification: court disputes, expert review, or situations where the other party may claim fabrication.