Secure Message

Send and receive files in adroid in a safer way

Why we should trust Secure Message :

Source code: https://www.amazon.com/dp/B08BDZ5MM6

Now, you can send your encrypted mail using Whatsapp, Facebook Messenger or Telegram, or any other communication application in addition to Mail clients Like Gmail, Yahoo, Hotmail,...

- Both, sender and mail receiver need to have "Secure Message" installed on their phones to be able to encrypt and decrypt shared E-mail.

- "Secure Message" allows you to encrypt an E-mail (Message body or/and attachment) before sending it, you can use any "E-mail client" installed on your android phone to send your encrypted e-mail.

- Lockdown mail encrypted files use ".lef" format for "Lockdown Encrypted File".

- Click on any received ".lef" file, and it will be opened and decrypted automatically by "Secure Message".

Encryption :

- "Secure Message" use RSA public key 4096- bits for key exchange

- "Secure Message" use AES 256- bits for encryption.

- For Android API 28 or higher, setUnlockedDeviceRequired and setIsStrongBoxBacked if available on your device are enabled.

- "Secure Message" uses the android key store system for storing the private key.

- For more information please visit :

- https://developer.android.com/training/articles/keystore

- https://developer.android.com/reference/android/security/keystore/KeyGenParameterSpec.Builder

You should know :

- Always remember that your private key is linked to your phone, and not to your E-mail address.

- "Secure Message" is not an "E-mail client", you will not send or receive E-mail from it, lockdown mail helps you to prepare an encrypted E-mail regardless of the used E-mail client.

- If you lose your phone or you uninstall "Secure Message", you will not be able to decrypt your old received E-mails, because you will lose your private key, please decrypt your files and keep them in a safe place before uninstalling Lockdown mail.

For that, you will use this application at your own risk.

Limitation :

The maximum file attachment size is 20 Mo.

You can add only one attachment per E-mail.

Privacy policy :

- "Secure Message" does not collect, share, send any personal data.

- "Secure Message" does not collect, share, send the user private key or any other needed information for encryption or decryption.

- "Secure Message" does not need access to the internet for encryption or decryption.

- "Secure Message" does not require any special permission, it will ask only for storage access when you want to send an attachment.

FAQ :

Q) Using lockdown mail instead of PGP :

A) No, if you want to decrypt your emails on many platforms(windows, android, ios..), or you want to keep your emails by keeping a private key, we recommend that you use PGP instead of lockdown mail.

Lockdown mail works only on android devices (For now).

So, if it is the case, why using lockdown Mail:

"Secure Message" allows you to?

- Protect your private key.

- Using fast algorithms.

- Make smaller encrypted data size. ( Encrypting with lockdown mail makes files smaller than PGP files).

-Make easy sharing and decrypting "encrypted files" than PGP, using any communication or email application like Gmail, WhatsApp, Telegram,...

- Make easy sharing public key.

About :

This is the first application release, Let us know if you have any questions or comments.

E-mail: lockdown-chat@protonmail.com