Private Messenger|通訊線上App不用買-HotApp4Game

Do you want to be confident that your messages are really secure between your intended recipient and yourself only, and not seen by any unwanted third parties?

Private Messenger is an instant messaging application which enforces end-to-end privacy. In practice messages are always encrypted and decrypted on the device, before being transferred through the internet. This means that none other than the sender or recipient is able to see the message content, not even us. This way we can respect the privacy of our users.

NOTE

Version 1.3.0 included a major rewrite of storing local data on devices, making it more secure. Unfortunately, in some cases, a bug caused the app to crash right after opening. The latest version 1.3.1 addresses this issue. We apologize for the inconvenience.

FAQ

Q: How exactly do you ensure privacy between the sender and recipient?

A: We use public key cryptography. During registration, a key pair is generated for each user account. The private key always stays on the user's device, while the public key is deployed to our server mapped to the user account for discovery. Messages are encrypted on the sender's device using the recipient's public encryption key, relayed to the recipient via our servers, and finally decrypted on the recipient's device using their private decryption key. Additionally, the same key pair is used to verify the sender's digital signature. For more information, see http://en.wikipedia.org/wiki/Public-key_cryptography.

Q: How about messages already decrypted on my device, or other local settings?

A: All local information, including sent and received messages, contacts and personal settings, are stored in a special encrypted database, and not in plain text for example in default shared preferences or SQLite databases. This means that even if the database file is somehow compromised (for example in rooted devices), the actual stored data cannot be seen.

Q: What kind of information do you store on your servers?

A: In short, only the bare minimum. At least the account username and public key, and then any additional information if the user so chooses. We don't store any messages - we only relay them from the sender to the recipient. There would be no point anyway, since the message content is always encrypted, and there is no chance even for us to decrypt it.

Q: Why do you run ads?

A: Unfortunately, running the server-side infrastructure is not free. Our intention is to cover this, and other development costs by running unobtrusive banner ads. This way we can provide the app for free to our users. We might consider an option to remove the ads in the future either by an in-app purchase or a paid version of the app.

Q: Any planned updates or new features?

A: Since the app is quite new, we will of course fix any bugs that come up. Additionally, we at least plan to improve usability and add more message types than text, for example images, location, etc.