Digitally signed emails. What is it and how do digital signatures work?

Digital signatures and end-to-end email encryption

End-to-end encryption protect your message privacy, while digital signatures provide additional security attributes:

  • Sender verification: the sender is who he/she claims to be
  • Integrity: The message has not been altered during transit
  • Non-repudiation: the sender cannot deny having sent the message

A digital signature is similar to a handwritten signature.  However it offers far more security.

How do Digital signatures work?

digital signature


A digital signature only requires the sender (the signer) to have a pair of cryptographic keys (a private key and a public key). The message is signed locally on the sender’s device (using sender’s private key) and then verified by the receiver on his device (using sender’s public key). The process work as follows:

  1. Alice (sender) generates a keypair and shares her public key with Bob (a one-time pre-requisite).
  2. Alice signs the message using her private key in her device and sends the message to Bob.
  3. Bob receives the signed message on his device and verifies the signature using Alice’s public key.

Digital signatures are commonly referred to as ‘Electronic signatures’ and are widely used in both personal and professional context.

How to send digitally signed emails  using Mailfence

First generate your keypair, and share your public key.  Signing emails with Mailfence is as simple as being illustrated in the image below.

digital signatures

Sending and receiving signed emails using Mailfence.

Yes, Mailfence – secure and private email service has made it super easy!

You can also check our user guide for more details on how to sign OR sign & encrypt your messages and perform other key management operations.

Even more easy with our ‘Integrated key store’

end to end encryption and key management

A preview of our integrated keystore to perform key management – Mailfence

Mailfence has pioneered OpenPGP end-to-end email encryption and digital signatures by making it easy-to-use.

With an integrated account keystore, users can generate, export or import a keypair.  They can also manage their key or add recipient’s public keys.  All of this without any external plugin or add-on.

This gives users unprecedented control over their privacy.  In addition we offer complete reversibility.  A user can export his/her keypair, as well as all the other data stored in his/her account such as calendar, contacts and documents.

Digitally signing  without end-to-end encryption

In a recent post we explained that digital signatures combined with end-to-end encryption increases security.  However it can also be useful to sign email digitally without encrypting them:

  •  Digitally signing emails with attachments gives the assurance to the receiver of the email that both the content and the attachment have not been tampered with during transit. This increases the legal value of the email.
  • Compliance with legal & regulatory requirements in various environments (for e.g., sales contracts, vendor & supplier agreements, …)

Wanna learn more about OpenPGP digital signature best practices?

At Mailfence, we have designed an easy to use end-to-end encrypted email.  We believe that users have an absolute and irrevocable right to internet privacy.  In case you want to leave either Yahoo Mail  or Gmail, click on Yahoo Mail or Gmail migration to Mailfence .

Join the fight for online privacy and digital freedom.

Get your secure email!


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– Mailfence Team

Spread the word!

M Salman Nadeem

Information Security Analyst - Security Team | Mailfence

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