The user can choose the encryption algorithm among the following ones:
- QP-Dyn 64 bits (or higher in premium version)
- AES 128 bits
- 3DES 128 bits
- Great performance in terms of speed and CPU load
- Encrypted messages are stored in the App database. They are decrypted and shown as plain text only when the user wants to see them.
- Configurations and messages can be exported or imported from the SDCARD.
In the premium version:
- Messages can be encrypted with a session key. In this case the public key will be sent together with the message to allow decryption.
The App can be used with different SIMs. Each time the passphrase is typed, the App produces the private and the public key of the user.
These, together with the receiver public key, allow the creation of a shared secret key (SSK) which is then used to encrypt messages with the chosen algorithm.
The App includes a repository of public keys which can be updated through direct communication with the owner (add to send contact requests).
In the premium version is also possible to update the repository by:
- Downloading new keys from different kinds of certification authorities (web sites, PKI, ...).
- Loading from the SDcard directory.
- Pasting from clipboard.
At the first App access you will be asked to type a passphrase twice, in order to create your private-publica keys couple (SIGN UP). In the next accesses you will be asked to type the passphrase only once.
The 4 upper icons are:
- set: to modify the App settings
- sms: to see the list of contacts whose public key is stored and of active chats. Selecting one of them, messages are decrypted and shown with the contact name and image if existing in your address book. A long tap on a contact popups asking if you want to delete the contact or all its messages, or to save the contact in the address book. A single tap on a messages popups showing the encrypted text. A long tap on a message popups asking if you want to delete it.
- add: to send contact requests to others. You can access your address book to select the contact to invite.
- info: to access the user guide