Ciphermail encrypts and signs email messages using S/MIME. To lower the threshold for receiving encrypted email messages, we introduced Ciphermail Encrypted PDF. Ciphermail can put the email message in a PDF file, encrypt this file with a password and send it to recipient as an email attachment.
You can use this app to calculate the PDF one-time password. You need to initialize the app using a secret string that is used to calculate the passwords for each individual PDF.

Please note: this app can only be used for authenticating Ciphermail Encrypted PDF files. Do not install the app if you don't receive Ciphermail Encrypted PDFs.

This app can only be used for decrypting Ciphermail encrypted PDF files. If you have not received a Ciphermail PDF message, you have no practical use for this app.