Copiosus

Copiosus is just another P2P chat application.

This software is provided ``as is`` without warranties or conditions of any kind, either expressed or implied.

Please download this app only if:
- You care about security.
- You don`t care about a beautiful UI.
- You like to try alternative chat apps.

Lame features:
- Send messages.
- Send files and images.
- Block users.

Other features:
- Two factor authentication
- End-to-end encryption using an asymmetric key.
- Improved end-to-end security using a security key as a second factor which encrypts data using a shared symmetric key.
- Minimal privileges required.
- No in app purchases.
- No ads.

How does end-to-end encryption work in this app:
1. Whenever you send a message M a random symmetric key R is generated
2. R is encrypted using the asymmetric (public) key of the other user resulting in A
3. M is encrypted with R resulting in N
4. If security key S is set: N is encrypted by S
5. N and A is sent to the destination