CM4U (crypt message for you) is a simple and easy to use app, which can encrypt your personal messages amongst your partners. With this app you can send and receive encrypted text messages and emails. The messages are encrypted with a private key, which is defined when a new partner is added. The sent and received messages are password protected with a PIN number, so your personal and business conversations are safe from interception.

Advantages of CM4U
- Very high security. PIN request on every start of the app, reliable encryption
Both sent and received emails and text messages do not appear in your phone. Everything is securely hidden in the CM4U app.
- Simple and intuitive to use
- Individually defined partners, with the feature of choosing partners from the contacts list.
- Sending encrypted text messages in a conventional way (as in popular apps)
- Viewing encrypted text messages and emails without the need of decryption. If the email is also sent to any other mailbox, it is in encrypted form.

CM4U works on Android (v. 2.3.3 and newer). Both the sender and receiver of the encrypted messages must have CM4U installed, and have an identical encryption key. CM4U is not dependent on any other apps installed on the phone for sending and receiving messages.

The app is not limited in time of use, or in message quantity.

1. Installing the app
After the installation is finished the app starts automatically. The app requires a username and a 6 digit long PIN (numbers only). Without the PIN the app will not run, and you will not be able to see any messages. We advise you to use a non-guessable PIN and keep it in a safe place.

2. Defining partners
In the partners list you can define partners that you wish to communicate with. It is important to exchange Cod(string for encryption) with the people you want to exchange messages with.
You can use a different encryption string for each partner.
If you have defined contacts in your phone, you can add them to the apps contact list using the button with the figure on it.

3. Text messaging
In the SMS menu, click “New message”. Choose your partner, write your message in the appropriate field, and then click Send.
The history of sent and received messages is available by clicking the button Inbox, Sent on the right.

4. Sending emails
First you need to set up your email account:
User: email address (e.g. [email protected])
Password: login password for your email account
Incoming host: server for incoming mail (pop.gmail.com)
Outgoing host: server for outgoing mail (port 25) (smtp.gmail.com)
Outgoing port: pre POP3 : 110, pre IMAP : 143, 465-gmail
Autentification – tick, if server for outgoing mail requires authentication

After saving your email account with the “Save settings” button, you can create emails using the “New message” button. Browsing sent and received emails is available with the Inbox / Sent buttons on the right.

5. Deleting messages (email or text message)
Press and hold the message you wish to delete, a window will pop up to confirm deletion.

Due to safety reasons the app will lock if you switch to another application, or if the screen saver activates

Proclamation
The Author proclaims that for the safety and confidentiality of the users of CM4U, the encryption key is not saved on any other device, but the specific device that the app is installed on. The app does not collect or record user or phone information that the app is installed on. The author is not liable for the user’s data. In case of loss, theft or damage, user data can only be restored from the backup the user creates.

Backing up the users data
To save the user’s data externally, copy the file: cm4u.db3. This file contains encryption information. In case of restore, copy this file on your mobile after installing the app.

Recent changes:
- Works on Android version 4.0 and above
- User with version 1.3 or older have to delete database (sdcard\cm4u.db3)
- Inserted encrypted database