LibreOffice 4.5 to provide PDF signing and timestamping

Collabora Productivity has completed integration of trusted timestamping and digital signing into LibreOffice. Used extensively by governments and information security companies, these features make LibreOffice the first comprehensive Open Source PDF signing solution. The work was commissioned by Swiss non-profit Wilhelm Tux after a successful crowdfunding campaign in October.

Trusted timestamping will be released in upcoming LibreOffice 4.5. It securely tracks the creation and modification of documents — once a document has been timestamped, it is impossible to compromise or dispute its integrity. Certificate signing of PDFs, which Collabora recently published in LibreOffice 4.4, guarantees a document’s origin and authenticity. Combined, these new features enable LibreOffice to generate documents suitable for a wide variety of secure and legal settings.

“The addition of signatures and timestamps to LibreOffice makes LibreOffice the obvious for a range of buyers” says Michael Meeks, Vice President at Collabora Productivity. “These enterprise features are the latest to cater to professional users, and reflect the demanding environments to which LibreOffice is being deployed”.

The signatures that are produced are interoperable with all PDF readers supporting the PDF/A standard, including products from Adobe. The signing process makes use of certificates and cryptography native to the operating system used, with Windows versions of LibreOffice using Microsoft’s included certificate manager. Mac and Linux versions include the NSS cryptographic library shared by Mozilla Firefox. Industry standard x.509 certificates are used for signing documents, and can be obtained from a wide range of certificate authorities.

Trusted timestamping implements IETF standard RFC 3161, and requires validation from a Time Stamping Authority (TSA). Several TSA’s provide the service free of charge, while Open Source TSA server applications may be deployed and operated independently.

“The use of PDF signatures and timestamps is required by Swiss law in many regulations concerning the exchange of documents with Government bodies, including the EÖBV for notary documents, and ElDI-V for tax receipts” said Markus Wernig, Chairman of Wilhelm Tux. “I’m pleased and amazed that Collabora have achieved the features in such a short time”.

About Collabora Productivity:
Collabora Productivity delivers LibreOffice products and consulting. With the largest team of certified LibreOffice engineers, it is a leading contributor to the LibreOffice code base and community. LibreOffice-from-Collabora provides a business-hardened office suite with long term multi-platform support. Collabora Productivity is a division of Collabora Ltd., the global software consultancy specializing in providing the benefits of Open Source to the commercial world, specialising in automotive, semiconductors, digital TV and consumer electronics industries.
About Wilhelm Tux:
Wilhelm Tux is a Swiss non-profit, non-government organisation founded in 2002. It’s focus is advocating Free and Open Source Software, the use of Open Standards in the public sector, and on protection of digital civil liberties. The group and it’s partners work to establish a favourable environment for the adoption of Free Software in Switzerland. In the past Wilhelm Tux served as a member of the constituting committee of the Swiss standardization body eCH, and has since taken an active role in public debate on digital issues within the public sector.

Mutual business crowdfunding for LibreOffice results in new features investment

A document being signed by hand

Last Friday Wilhelm Tux, a Swiss community group, reached their €8,000 (CHF 10.000) crowdfunding target for LibreOffice. The money will be used to add support for digital signatures in PDF documents in a secure and compliant way. From announcement to completion took four days.Once implemented, LibreOffice will be able to:

  • Create PDF documents with legally accepted digital signatures
  • Conform to PDF/A signature standards
  • Use Mozilla Firefox or Thunderbird to manage certificates using a simple interface


Wilhelm Tux has established a strong network of business users of Open Source over the last 12 years, including companies founded by members of the organisation themselves. Even taking this network into consideration however, the speed with which funds were raised is impressive for a local advocacy group with little media experience.

The success of their campaign shows that Swiss businesses want LibreOffice, want digital signing, and, given the opportunity, are happy to pay for it. It also demonstrates the freedom that the LibreOffice ecosystem provides to businesses. Independently of The Document Foundation who steward and steer LibreOffice development, and independently of the many businesses who have stakes in the future of the application, organisations of any size can organise the addition of new features. When their needs are shared, they need not even bear the exclusive burden of cost.

Wilheml Tux logo
Logo of Wilhelm Tux


25 Businesses and 65 individuals contributed to the campaign. These 90 interested parties will have their wish fulfilled by April 2015, when the features are due to be delivered. More importantly however, the cost of implementing these new features was shared 90 times.

Uniting disparate groups with shared interests to invest in solutions for mutual benefit is sometimes referred to by crowdfunding marketers as “co-funding” or “mutualisation”. It has particular relevance to Open Source.

The role of Wilhelm Tux in this campaign was similar to that of an Internet dating agency. They identified people with similar needs, and introduced them to each other using a framework designed to keep the participants safe. Wilhelm Tux acted as treasurer, guaranteeing and safeguarding payments, and also as supervisor – undertaking to manage completion of development and assure quality.

By contrast, undertaking to contract Microsoft, Apple, or Google to make customisations, however minor, is well beyond reach of most trade associations and community groups. Users seeking improvements to Office 365, iWork, or Google Docs have few avenues to pursue.

Work on PDF digital signatures was partially completed in 2012, but then stagnated. Instead of pressuring volunteer developers to pick up the project, or The Document Foundation (who do not undertake LibreOffice development directly), Wilhelm Tux proactively sought out an independent company to complete the work.


The LibreOffice community conference in Bern last September provided an opportunity for Wilhelm Tux to meet with Collabora Productivity GM Michael Meeks, and scope out the task in-person with Collabra developers. As they explain on their campaign page, Wilhelm Tux chose Collabora due to our enterprise experience, staff of core LibreOffice developers, and commitment to publishing all changes upstream to the Open Source edition of LibreOffice. As their website states:

“That all customer-specific modifications are merged back into the free development branch (“main tree”) of LibreOffice was, for us, the main reason why we chose Collabora as our partner for this project, as it means that we can ensure that PDF signatures will be freely available for all users world-wide” — Wilhelm Tux website

3x Win

This business model of Open Source development therefore provides a rare case of win-win-win. The 90 business and individuals who backed PDF digital signatures get the features that they need at a fraction of the total cost of their development, from a proven company with enterprise expertise. Collabora get a new contract for work that they can deliver efficiently, and which will improve the usefulness of their product to other customers. But in addition to the textbook two-way “win”, a third win is also achieved: a win for all people who may use LibreOffice, for now, and for the future.

As these features will also make their way back into Open Source LibreOffice and products based upon it, ultimately the widest possible audience will enjoy the benefit — without any detriment to the project’s 90 investors, or to the development team who will deliver it.

Although contracts such as this make up a small proportion of Collabora’s work on LibreOffice, being able to fulfil the productivity needs of the highly diverse range of people using LibreOffice adds strength and flexibility to our business and position in the Open Source ecosystem.