MailDroid allows you to sign and/or encrypt your emails prior to sending using either S/MIME, PGP/MIME, or PGP Inline mode using the Flipdog Solutions Encryption Plugin available free on the Google Play Store.
Algorithm options in MailDroid
- S/MIME: Secure MIME is a version of the MIME protocol that allows for encryption and signing of email messages and contents using an asymmetric encryption algorithm
- PGP/MIME: A cleaner approach not supported by all clients but using RFC 2015. This has a new MIME type to allow separation of the signed data and the signature
- PGP Inline: The traditional clear-signing an email using openPGP. This puts the signature/encryption in-line with the text you are signing/encrypting
Signing with S/MIME
- Select S/MIME from the the dropdown box and click the sign checkbox
- Signing will be done with your private certificate and the user who gets the email will validate against your public certificate
- Your private certificate will be shown in the headers area of the email, you can click on the 'i' icon to get more details. You can also click 'Load More' which will show more available certificates in case you want to sign with another cert
Signing with PGP/MIME or PGP Inline
- Select PGP/MIME or PGP Inline from the the dropdown box and click the sign checkbox
- Signing will be done with your private key and the user who gets the email will validate against your public key
- Your private key will be shown in the headers area of the email, you can click on the 'i' icon to get more details. You can also click 'Load More' which will show more available keys in case you want to sign with another key
Encryption with S/MIME
- Select S/MIME from the the dropdown box and click the encrypt checkbox
- Encryption will be done with your private certificate and the user who gets the email will validate against your public certificate
- Your private certificate will be shown in the headers area of the email, you can click on the 'i' icon to get more details. You can also click 'Load More' which will show more available certificates in case you want to encrypt with another cert
Encryption with PGP/MIME and PGP Inline
- Select PGP/MIME or PGP Inline from the the dropdown box and click the encrypt checkbox
- Encryption will be done with your private key and the user who gets the email will validate against your public key
- Your private key will be shown in the headers area of the email, you can click on the 'i' icon to get more details. You can also click 'Load More' which will show more available keys in case you want to encrypt with another key
You can also sign and encrypt an email by clicking both checkboxes.
To summarize, MailDroid will allow you to choose one of two algorithms to sign and encrypt your mail. This is an advanced feature and users should read up on the basics of each approach prior to using them.
In the future, more options may be added to this feature.