Private Office Suites: Encrypted, Self-Hosted, or Desktop

By State of Surveillance Published: 2026-08-17

The Short Version

  • The phrase "private office suite" covers three structurally different designs. Sorting the products into the right group matters more than ranking them.
  • Hosted and end-to-end encrypted: CryptPad and Proton Docs both state, in their own words, that the document is encrypted so the service cannot read it.
  • Self-hosted: OnlyOffice, Nextcloud Office and Collabora Online move the server to infrastructure you control. That changes who holds the data, which is a real gain, but it is not the same property as end-to-end encryption.
  • Desktop: LibreOffice runs on the machine, with no service in the loop.
  • CryptPad documents its own limit: encryption of content does not hide the connection, and the instance can see an IP address and browser details.
  • Skiff, still listed in circulating privacy round-ups, is gone. Its own site now says it joined Notion and that services were sunset.

One label, three different designs

Documents are where a lot of the most sensitive material actually sits: contracts, medical notes, client lists, drafts of things that are not public yet. The tools marketed as private alternatives to the mainstream suites are not variations on a single idea. They fall into three groups, and the groups protect different things.

  1. Hosted, with end-to-end encryption. The file is encrypted before it reaches the service, and the operator states that its own servers cannot read the contents.
  2. Self-hosted. The editing software runs on infrastructure you or your organisation administer. The question of a third-party host reading the file is replaced by the question of who runs, patches and backs up your server.
  3. Desktop. An application installed locally, with no service involved at all.

Conflating the first two groups is the usual mistake. Self-hosting relocates the data, which is often the decisive change for an organisation with its own compliance obligations, but relocating data is not the same guarantee as content the host is unable to decrypt. Either can be the right answer; they answer different questions, and a vendor page will rarely draw the line for you. The same split shows up in adjacent categories, including encrypted cloud storage, where "encrypted" is applied to several unrelated designs.

Group one: the service states it cannot read the file

CryptPad's security documentation puts the claim plainly: CryptPad is end-to-end encrypted and the server has no access to your data.[3] The project is under an AGPL-3.0 licence and its repository was last pushed on 14 August 2026.[9]

Proton Docs makes a comparable claim. The address proton.me/docs redirects to the Proton Drive documents page, titled "Create and collaborate with secure online documents | Proton", which presents the product as an end-to-end encrypted, real-time collaborative document editor and frames it as protection against data breaches, surveillance and use of the contents for AI training.[2]

Both vendors state the property as a fact about the system rather than a promise of restraint. CryptPad, though, qualifies its own claim on the same page, and the qualification matters. The sentence sits under a heading, "Trust Assumptions", and is followed by a list of them: the instance must run the same code as the one published on GitHub, not block your network messages, and follow its terms of service and privacy policy, and collaborators must not forward sharing links. Only [u]nder these assumptions, CryptPad writes, can you be sure that it is technically not possible to read or modify your documents by your chosen CryptPad instance.[3] A hosted instance serving modified code is outside what the encryption can prove. Encryption of content, in any case, covers content only.

CryptPad on its own limits

CryptPad's documentation is unusually direct about the edge of what encryption does. The trust assumptions above are the larger of its two published caveats, since the guarantee is contingent on the instance serving the published code. The second concerns metadata:

CryptPad does only provide a weak form of anonymity. Your chosen CryptPad instance can see your IP address and your "user agent" (browser and operating system).[3]

That is a statement about metadata rather than content. The instance operator can observe that a connection happened, roughly from where, and with what software, while the document text itself stays unreadable to them. For most threat models this is an acceptable trade. For anyone whose exposure is the fact of the connection rather than the text, it is the whole problem. A project that publishes its own weak points is easier to evaluate than one that publishes only its strengths.

Group two: you become the host

Three widely deployed suites are built to run on infrastructure you control.

OnlyOffice. The project's home page describes the suite as distributed under the AGPL 3.0 license, and the licence recorded for the DocumentServer repository is likewise AGPL-3.0.[4][10] That repository was last pushed on 22 July 2026.[10] The same home page carries a bullet reading Three levels of encryption: at rest, in transit, end-to-end.[4] The page does not elaborate on who holds the keys or where encryption happens, so that line should not be read as the same claim CryptPad and Proton make about the server being unable to decrypt.

Nextcloud Office. Nextcloud sells this under more than one engine, which is the first thing to establish before asking about licences. Its product menu lists "Nextcloud Office Powered by Euro-Office" and "Nextcloud Office Powered by Collabora" as separate entries, alongside a third suite, and badges the page as "Open source software built in Europe". The same page lists DOCX, ODT, PDF and Markdown among the formats its document component supports.[5] Licensing therefore has to be stated per component rather than per product. The Collabora connector app, richdocuments, declares AGPL-3.0-or-later in its own appinfo/info.xml and names itself "Nextcloud Office (Collabora)"; its repository was pushed on 16 August 2026.[11] That licence covers the connector only. The rendering engine behind either variant carries its own separate terms, which the product page does not state.

Collabora Online. Its site describes it as a powerful online document editing suite. Integrate into your own infrastructure or access via one of our trusted hosting partners.[6] The licence is MPL-2.0, confirmed by reading the COPYING file at the repository root, which begins This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.[8]

Two cautions follow from that last check. GitHub's automated licence detection reports the Collabora repository as Other or NOASSERTION, which is why the COPYING file was read directly.[12] Automated licence labels are a convenience, not an authority. And the same repository states that it is an Issue tracker only. Active development is on Gerrit at https://gerrit.collaboraoffice.com/, so commit timestamps there say nothing about how actively the project is developed.[12]

One more thing to be precise about: beyond OnlyOffice's unelaborated bullet, none of the three vendor pages cited above describes an end-to-end model in which the operator is unable to read documents. That is a statement about what those pages say, not a finding about what the software does or does not implement. Anyone who needs that specific property should put the question to the vendor and ask for the documentation. Choosing to self-host is usually part of a wider decision about where an entire workspace lives, which is the subject of the private cloud suite comparison.

Group three: no host at all

LibreOffice is the desktop option, and the category it occupies is simply different: files stay on the machine unless they are deliberately moved somewhere else, so there is no operator, no instance and no server log to reason about. Its licensing is stated on the project's own page: LibreOffice is made available subject to the terms of the Mozilla Public License v2.0 ... It is based on code from Apache OpenOffice made available under the Apache License 2.0 but also includes software which differs from version to version under a large variety of other Open Source licenses.[7] The primary licence is MPL v2.0, and the mixed-licence caveat is the project's own.

The category churns, and round-ups do not

Skiff appears in privacy recommendation lists that are still circulating. It is not available. The company's own site now reads: We are excited to share that Skiff has joined Notion. and On Feb 9th, we announced that Skiff was acquired by Notion and that services would be sunset on August 9th with email forwarding enabled for those who chose to be extended to Feb 9th 2025.[1] The page does not state the year of that original announcement.

The practical lesson generalises past one product. Recommendation lists outlive the products they recommend, and a privacy tool that gets acquired can stop existing on a published schedule. Before acting on any list, including this one, open the vendor's own home page and confirm the product is still being sold. The same check applies to every entry in the privacy tool comparison hub.

How to read the next vendor page you open

Five questions separate the marketing from the property being purchased.

  • Does the page say the service cannot read the contents, or only that data is encrypted? Encryption at rest and in transit is close to universal and says nothing about who holds keys.
  • If the page says end-to-end, does it say where encryption happens and who holds the keys? An unexplained bullet is not a guarantee.
  • What does the project say about metadata? CryptPad's account of IP addresses and user agents is the model of what an honest answer looks like.
  • What licence is in the LICENSE or COPYING file? Read the file rather than an auto-detected badge.
  • Where does development actually happen? A quiet mirror can hide an active project, as with Collabora and its Gerrit instance.

Pick the group first. If the requirement is that no operator can read the text, group one is the only one whose vendors currently make that claim explicitly. If the requirement is that the data stays on infrastructure under your control, group two is built for it. If the requirement is that no service touches the file at all, the desktop answer has been sitting there the whole time.

Sources

  1. Skiff, "Skiff has joined Notion". No publication date given; retrieved 17 August 2026.
  2. Proton, "Create and collaborate with secure online documents". No publication date given; retrieved 17 August 2026.
  3. CryptPad Documentation, "Security". No publication date given; retrieved 17 August 2026.
  4. OnlyOffice, home page. No publication date given; retrieved 17 August 2026.
  5. Nextcloud, "Nextcloud Office". No publication date given; retrieved 17 August 2026.
  6. Collabora Online, home page. No publication date given; retrieved 17 August 2026.
  7. LibreOffice, "Licenses". No publication date given; retrieved 17 August 2026.
  8. Collabora Online, COPYING file (repository root). No publication date given; retrieved 17 August 2026.
  9. GitHub, CryptPad repository (licence and last-push metadata). Repository metadata; retrieved 17 August 2026.
  10. GitHub, ONLYOFFICE DocumentServer repository (licence and last-push metadata). Repository metadata; retrieved 17 August 2026.
  11. GitHub, Nextcloud richdocuments repository (appinfo/info.xml and last-push metadata). Repository metadata; retrieved 17 August 2026.
  12. GitHub, Collabora Online repository (description and detected licence). Repository metadata; retrieved 17 August 2026.