An ATSOFTS file contains one or more files encrypted by LetEncrypt, an online file encryption service. It stores encrypted information about the files, which includes metadata that describes each encrypted file. ATSOFTS files are saved in XML format and can only be decrypted by LetEncrypt.

ATSOFTS are created when a user uploads a file, such as a .DOCX or .PDF file, to LetEncrypt, encrypts it, and downloads the file. To do this, select "Encrypt," drag and drop your file on to the encryption method in the window, click Submit, and then click Download. Save the key that appears on this screen in order to decrypt the encrypted ATSOFTS file. To decrypt the ATSOFTS file in LetEncrypt, select "Decrypt," drag and drop your file on to the decryption area in the window, enter your decryption key, and click the unlock icon. NOTE: atSofts LetEncrypt has been discontinued.