Apparatus and associated methods relate to securely transmitting, directly between two mobile devices, AES-256 encrypted file attachments which are decrypted within an application program (APP) using a decryption key that is available only to the APP. In an illustrative embodiment, the encrypted file may be attached to an e-mail. The e-mail may be transmitted directly to another mobile device via direct Wi-Fi, for example. The e-mail may be transmitted directly to another mobile device using Bluetooth, for example. In encrypted attachment may be deciphered only within the APP running on the receiving mobile device using a private key accessible to only the APP.