Mailvelope v5.1 - a significant leap forward

By Bernhard Spirkl - April 30, 2024
Mailvelope v5 improvements
Mailvelope improved signature handling and hardened its key server

Mailvelope v5.1.2 marks a significant leap forward in its evolution. Alongside notable advancements in technical sophistication and security measures, we have also enhanced usability, particularly focusing on key management and message signing capabilities.

Mailvelope's progression from version 5.0.0 (April 2023) to 5.1.2 (February 2024) was driven by three primary objectives:

  • Enhanced cryptographic capabilities. We aligned with OpenPGP.js version 5.0 and improved our architecture by removing legacy modules.
  • Strengthened Mailvelope key server. We improved usability as well as resilience against potential threats.
  • Improved signature handling. From both technical and usability standpoints, we are now able to ensure robustness and ease in daily use.

We were also successful in streamlining the onboarding process. A collaboration with UX experts Superbloom was an invaluable help in this task. In particular, their user analyses helped us to better see and overcome our own "blind spots" in user guidance. Our "Get Started" guide now gives the right advice for every situation our users might face and is available in five languages.

Improved handling of signatures

A positive side effect of the adaptations to OpenPGP.js v5.0 was that Mailvelope has been able to improve the handling of PGP signatures on many levels. Mailvelope version 5.1.0 (released in July 2023) brought enhancements to signature verification. Besides some fixes a warning message is now displayed if the signature does not match user identities on sender key:

Mailvelope detected an adress mismatch

As the correct handling of signatures is essential for secure email communication, Mailvelope made checking signatures more user friendly by displaying a warning it it detects any mismatch between sender email and the signature of the email.

File decryption UI shows result of signature verification

Also signature verification results are now displayed to the user in the file decryption UI. Previously this feature was only available using GnuPG as Mailvelope main keyring.

Solving key server challenges

The Mailvelope key server is a crucial component of our software architecture. One of the key features that has significantly contributed to the popularity of Mailvelope is the seamless ability to locate the correct public key by simply entering the email address, without the need for manual searching (provided the recipient also uses Mailvelope). However, for this mechanism to be secure, it is imperative to verify that the associated key indeed belongs to the claimed email address. To address this, the Mailvelope key server always relied on a validation mechanism that sends an encrypted email to the specified email address whenever a new key is uploaded or removed.

As Mailvelope aims to facilitate communication not only among its own users but also with those using other PGP encryption and decryption applications, a solution was required for cases where the recipient's public key is not hosted on the Mailvelope key server. This became particularly urgent after the SKS keyserver network, which had been relied upon for decades, had to be switched off due to severe attacks on their infrastructure.[1]

With Mailvelope version 5.0 and subsequent minor releases, we have successfully addressed these challenges. The keyserver's codebase has been reorganized to enhance its resilience against potential flooding attacks, and the existing database has been purged of all third-party certificates. While these changes are behind-the-scenes improvements, several new features have also been introduced to the user interface.

Improvements in Key search UI

In addition to these backend changes, several adjustments are now visible to users. By default, Mailvelope now exclusively supports the key servers and, both classified as "verifying key servers" that utilize the aforementioned mechanism to ensure key identities are secure.

The renewed Mailvelope key saerch UI

With a click on “change” the user gets directed to the key directories options page in order to define its individual preferences.

Options to choose different key directories for search

Furthermore, the key search feature has been improved for usability, allowing users to search for keys across multiple key servers using email addresses, key IDs, or fingerprints. Once one or more keys are located, users can directly import them into the Mailvelope keyring.

Mailvelope asks for confirmation to import a found key

Looking Forward

We want to express our appreciation to the OTF IFF Fund for their generous support, which has made all these improvements possible. At Mailvelope, our goal is to make email encryption on webmail services more widely known and adopted as a common practice. There's still much work ahead to achieve this goal, but with the support and enthusiasm of our user community and funding like that from OTF, we're confident we'll continue to improve and make a significant impact on data security. This benefits both individuals who value the protection of their personal data and businesses and organizations looking to enhance the security of their communications.

Try Mailvelope now

To try our Community Version for free, just refer to our user-friendly "Get Started" guide to begin. Community Version users are invited to show their support by making a donation (scroll down) on our website, helping us enhance and maintain our offerings. For Google Workspace business users and organization heads, explore Mailvelope Business with a 14-day trial or get in touch to discuss personalized options.

[1] More on this incident can be read here: