We regularly hear news about breakthroughs leading to the advent of working quantum computers. For now, such a computer doesn’t exist, so nobody can use one to crack encryption. But when it does arrive, it’ll already be too late to address the problem. That’s why new encryption algorithms that are resistant to both classical hacking methods and quantum-computer attacks are being standardized today. These algorithms are known as post-quantum or quantum-resistant. Support for these algorithms is gradually appearing in everyday devices and applications — they were recently integrated into Google Chrome. This, by the way, immediately exposed compatibility issues within standard organizational IT infrastructures. So, where have post-quantum algorithms already been implemented, and what should IT teams prepare for?

Which services already support post-quantum algorithms?

Amazon. The cloud giant introduced a “post-quantum” variant of TLS 1.3 for its AWS Key Management Service (KMS) back in 2020. Since then, the solution has been updated, adapting its configuration settings in line with NIST recommendations.

Apple iOS/iPadOS/macOS. In February 2024, Apple announced an update to the iMessage protocol, which will use the PQ3 quantum-resistant protocol for key exchange. It’s based on the NIST-recommended Kyber algorithm, but also utilizes classical elliptic-curve cryptography, providing dual-layer encryption.

Cloudflare. Since September 2023, Cloudflare has supported post-quantum key agreement algorithms for establishing connections to origin servers (client websites), and is gradually rolling out support for post-quantum cryptography for client connections. The technology is used when establishing a TLS connection with compatible servers/clients, applying a dual key agreement algorithm: classical X25519 for one part of the key, and post-quantum Kyber for the other. This popular combination is known as X25519Kyber768.

Google Chrome. Test support for post-quantum cryptography for establishing TLS connections appeared in August 2023, and as of version 124 in April 2024, it’s enabled by default. The algorithm used is X25519Kyber768.

Mozilla Firefox. Support for X25519Kyber768 for TLS and QUIC appeared at the beginning of 2024, but it’s still not enabled by default and must be activated manually.

Mullvad. This popular VPN service uses the following PQC method: first, a traditional encrypted connection is established, after which a new key agreement is conducted using the Classic McEliece and Kyber algorithms. The connection is then re-established with these keys.

Signal. The messenger implemented the PQDXH protocol in September 2023, using the same X25519Kyber768 mechanism.

Tuta(nota). The popular secure email service allows users to send post-quantum encrypted emails using the X25519Kyber768 algorithm. However, the obvious drawback is that this only works when communicating with other Tuta users.

Although not yet a commercial product, it’s also worth mentioning Google’s implementation of FIDO2 hardware security keys, which use a combination of classical ECDSA and post-quantum Dilithium.

In addition to these, PQC is supported by numerous libraries that serve as the foundation for other products, from email and web servers to operating systems. Notable libraries include OpenSSL and BoringSSL, as well as the experimental branch of Debian. Many of these implementations have been made possible thanks to the Open Quantum Safe initiative, which supports post-quantum forks of popular cryptographic utilities and libraries, available for a variety of popular programming languages.

The main drawbacks of quantum-resistant cryptography

The algorithms haven’t been sufficiently analyzed. Although the broader scientific community has been conducting cryptanalysis for several years, the mathematical principles behind post-quantum cryptography are more complex. Moreover, experience with classical cryptography shows that serious flaws or new attack methods can sometimes be discovered decades later. It’s almost certain that vulnerabilities will be found in modern PQC algorithms — not just implementation vulnerabilities, but fundamental algorithmic defects.
Key sizes are significantly larger than in RSA and ECC. For example, the Kyber768 post-quantum algorithm has a public key size of 2400 bytes. This leads to a significant increase in data transmission volumes if key renegotiation occurs frequently. In tightly designed or low-power systems, there might not be enough memory for such large keys.
The computational load of PQC is also higher than classical, which slows down operations and increases energy consumption by 2–3 times. However, this issue may be resolved in the future with optimized hardware.
Compatibility issues. All updates to encryption standards and protocols — even classical ones — create complications when some systems have been updated and other related ones haven’t.

Post-quantum compatibility problems

Practical issues will primarily affect services using the TLS protocol for connections. TLS is implemented in numerous ways across thousands of products — sometimes with errors. As soon as Google enabled Kyber support by default in Chromium 124, administrators started reporting that Chrome and Edge couldn’t establish connections with web servers, as they would immediately disconnect with an error after the ClientHello TLS handshake. This issue was caused by problem number two: the large key size. As a result, the ClientHello TLS message, which always fitted into a single TCP packet, expanded into multiple packets, and so servers, proxies, and firewalls not prepared for this larger ClientHello message would immediately terminate the connection. Appropriate behavior would involve reading the following packets and agreeing on an older, classical encryption algorithm with the client. A list of incompatible web servers and firewalls affected by this issue is being tracked on a dedicated site, with Cisco notably listed.

If an organization suddenly can’t open any websites, the problem is likely with the proxy or firewall, which needs an update. Until the developers of incompatible applications and devices release patches, a temporary solution is to disable PQC:

using MS Edge and Chrome group policies
in Chrome’s advanced settings: chrome://flags/#enable-tls13-kyber
in Firefox’s settings: about:config -> security.tls.enable_kyber

Administrators are advised to check their websites and web applications by enabling Kyber support in Firefox or Chrome and attempting to access the site. If an SSL/TLS error occurs, the web server needs to be updated.

Quantum-resistant cryptography standards

Standardization is key to preventing a “protocol mess” and compatibility issues. For PQC, this process is ongoing but far from complete.

NIST recently introduced the first full-fledged standards for post-quantum cryptography — FIPS 203, FIPS 204, and FIPS 205. Essentially, these are CRYSTALS-Kyber for key exchange, along with CRYSTALS-Dilithium and SPHINCS+ for various digital-signature scenarios.

European organizations  from — ENISA and ETSI to BSI and ANSSI — intend to adopt NIST’s standards but are open to considering additional algorithms if they prove to be better. They all emphasize the necessity of double encryption for critical data — using both post-quantum and classical algorithms simultaneously. Given the novelty of post-quantum algorithms, innovative methods of breaking them may emerge, which is why the second layer of encryption is recommended.

China plans to standardize post-quantum algorithms in 2025. The Chinese Association for Cryptologic Research (CACR) announced the finalists in 2020: Aigis-sig and Aigis-enc (modified relatives of CRYSTALS-Kyber and CRYSTALS-Dilithium) and LAC.PKE.

Meanwhile, the IETF working group responsible for internet protocols will likely endorse the use of cryptography standards proposed by NIST in these protocols.

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A corrupted hard drive no longer need lead to the loss of all your data. Today there are cloud services: mail is stored in Gmail, files in Dropbox, notes in Apple Notes, and so on. But even with cloud services there’s no doing without backup. Instead of corrupted drives, they present other surprises: for example, they might shutter, hike subscription prices, lose your data, or use it to train AI. And if your internet ever goes down, online-only data is useless.

So as not to be caught off guard by sudden unavailability or policy changes, always back up your data on your own computer and protect it against ransomware. And backups need to be both readable and usable without proprietary software. They should be able to either be exported to common standard formats (PDF, HTML), or migrated to a “backup” app that works offline and without a subscription.

There is no universal recipe here: each online service has its own procedure. Today we look at backing up data in Notion — a knowledge base and note-taking app.

Backup

Notion lets you export data in one of three formats: PDF, HTML or Markdown+CSV. You can export a single note, a group of notes, or even an entire database. But only business and enterprise subscribers can do a full export to PDF format.

For most apps, we recommend exporting to HTML format, as it’s free, saves all types of data, and can be viewed in any browser with no special software required.

You can do the exporting on a desktop computer or mobile device. For small amounts of data, a ZIP-archive download is immediate; for large amounts, you receive a download link by email — which arrives with some delay.

To export several notes or a subpage, press the advanced menu icon (•••), select Export, specify HTML as the export format, and include subpages and all types of content (Everything).

An entire workspace can be exported from the desktop app or web interface. Go to the settings, and under Workspace → Settings, click Export all workspace content. In addition to the above settings, be sure to enable Create folder for subpages.

Only workspace administrators have this export option. For teamspaces, the export won’t include other users’ personal (hidden) pages created within the teamspace.

Having unzipped the archive on your computer to a separate folder, you can open the index.html file in it with any browser and freely navigate through your notes.

Export to Obsidian or AFFiNE

To not only view saved notes but also be able to edit them without Notion, you have to migrate your data to another, similar app that works offline or on a server under your control. The list of possible alternatives to Notion warrants a long read all of its own, so here we’ll limit ourselves to just two apps that Notion users often recommend as a substitute.

Obsidian is an app for structured data storage that can work entirely offline, free of charge. There’s a paid service — Obsidian Sync — for synchronizing multiple devices, but users manage without it by placing the storage (vault) in an iCloud folder, or by using third-party plugins for synchronization with SFTP, Amazon S3, Dropbox or other services.

To migrate data from Notion to Obsidian:

Perform a full export of the Notion workspace as per the above instructions.
Install Obsidian and the official import plugin.
Create a vault in Obsidian for the migrated data.
Activate the installed plugin under Settings → Community plugins in Obsidian.
Start the import via the button on the vertical command bar on the left.
Select Notion (.zip) as the import file format, and in the dialog, specify the ZIP file downloaded during export.
Enable Save parent pages in subfolders.
Press Import.
Wait for the import to finish.

For very large databases, you may encounter problems with importing embedded ZIP files, in which case see the help page on the Obsidian website.

AFFiNE is an open-source app offering a workspace with fully merged docs, whiteboards and databases, replacing, the developers say, both Notion and Miro. The business model is based on paid plans and AI assistants, but the app can work offline and even function as a standalone server wholly on your own infrastructure.

Content export from Notion is built right into the AFFiNE desktop app, so the procedure is quite straightforward:

Perform a full export from Notion.
Unzip the file to a separate folder on your computer.
Install AFFiNE and create a workspace.
Run the import by going to All pages → New Page → More options → Import page.
Choose import from markdown files, and select the html file from the unpacked folder.

Visit the AFFiNE website for a video guide to importing from Notion.

And remember to protect local backups of your important data against stealers and ransomware with the help of Kaspersky Premium.

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After many years of research and testing, in mid-August 2023, the U.S. National Institute of Standards and Technology (NIST) finally introduced fully-fledged post-quantum encryption standards — FIPS 203, FIPS 204, and FIPS 205. So let’s discuss them and see why they should be adopted as soon as possible.

Why do we need post-quantum cryptography?

First, let’s briefly outline the threat quantum computers pose to cryptography. The issue lies in the fact that quantum computing can be used to break asymmetric encryption. Why is this important? As a rule, today’s communication encryption typically uses a dual system:

All messages are encrypted using a symmetric algorithm (like AES), which involves a single key shared by all participants. Symmetric algorithms work well and fast, but there’s a problem: the key must be somehow securely transmitted between interlocutors without being intercepted.
That’s why asymmetric encryption is used to transmit this key (like RSA or ECDH). Here, each participant has a pair of keys — a private and a public one — which are mathematically related. Messages are encrypted with the public key, and decrypted only with the private one. Asymmetric encryption is slower, so it’s impractical to use it for all messages.

The privacy of correspondence is ensured by the fact that calculating a private key from the corresponding public key is an extremely resource-intensive task — potentially taking decades, centuries, or even millions of years to solve. That is — if we’re using traditional computers.

Quantum computers significantly speed up such calculations. Specifically, Shor’s quantum algorithm can crack private keys for asymmetrical encryption much faster than its creators expected — in minutes or hours rather than years and centuries.

Once the private key for asymmetric encryption has been calculated, the symmetric key used to encrypt the main correspondence can also be obtained. Thus, the entire conversation can be read.

In addition to communication protocols, this also puts digital signatures at risk. In the majority of cases, digital signatures rely on the same asymmetric encryption algorithms (RSA, ECDSA) that are vulnerable to attacks by quantum computers.

Today’s symmetric encryption algorithms, on the other hand, are much less at risk from quantum computers than asymmetric ones. For example, in the case of AES, finding a 256-bit key using Grover’s quantum algorithm is like finding a 128-bit key on a regular computer. The same applies to hashing algorithms.

The trio of post-quantum cryptography standards: FIPS 203, FIPS 204, and FIPS 205

The primary task for cryptographers has become the development of quantum-resistant asymmetric encryption algorithms, which could be used in key transfer and digital signature mechanisms. The result of this effort: the post-quantum encryption standards FIPS 203, FIPS 204, and FIPS 205, introduced by the U.S. National Institute of Standards and Technology (NIST).

FIPS 203

FIPS 203 describes a key encapsulation mechanism based on lattice theory — ML-KEM (Module-Lattice-Based Key-Encapsulation Mechanism). This asymmetric cryptographic system — which is resistant to quantum algorithm attacks — is designed to transfer encryption keys between interlocutors.

ML-KEM was developed as part of CRYSTALS (Cryptographic Suite for Algebraic Lattices) and is also known as CRYSTALS-Kyber, or simply Kyber.

FIPS 203 features three parameter variants for ML-KEM:

ML-KEM-512: Security level 1 (equivalent to AES-128);
ML-KEM-768: Security level 3 (equivalent to AES-192);
ML-KEM-1024: Security level 5 (equivalent to AES-256).

FIPS 204

FIPS 204 defines a digital signature mechanism, also based on algebraic lattices, called ML-DSA (Module-Lattice-Based Digital Signature Algorithm). Previously known as CRYSTALS-Dilithium, this mechanism was developed within the same CRYSTALS project as Kyber.

FIPS 204 has three parameter variants for ML-DSA:

ML-DSA-44: Security level 2 (equivalent to SHA3-256);
ML-DSA-65: Security level 3;
ML-DSA-87: Security level 5.

FIPS 205

The third standard, FIPS 205, describes an alternative digital signature mechanism: SLH-DSA (Stateless Hash-Based Digital Signature Algorithm). Unlike the other two cryptosystems, which are based on algebraic lattices, SLH-DSA is based on hashing. This mechanism is also known as SPHINCS+.

This standard involves the use of both the SHA2 hash function with a fixed output length, as well as the SHAKE function with an arbitrary length. For each base cryptographic-strength level, SLH-DSA offers sets of parameters optimized for a higher speed (f — fast), or a smaller signature size (s — small). Thus, FIPS 205 has more variety — with as many as 12 parameter options:

SLH-DSA-SHA2-128s, SLH-DSA-SHAKE-128s, SLH-DSA-SHA2-128f, SLH-DSA-SHAKE-128f: Security level 1;
SLH-DSA-SHA2-192s, SLH-DSA-SHAKE-192s, SLH-DSA-SHA2-192f, SLH-DSA-SHAKE-192f: Security level 3;
SLH-DSA-SHA2-256s, SLH-DSA-SHAKE-256s, SLH-DSA-SHA2-256f, SLH-DSA-SHAKE-256f: Security level 5.

HNDL, and why it’s time to start using post-quantum encryption

For now, the threat of quantum algorithms breaking asymmetric encryption is mostly theoretical. Existing quantum computers lack the power to actually do it in practice.

Until last year, it was believed that sufficiently powerful quantum systems were still a decade away. However, a 2023 paper suggested ways to optimize hacking using a combination of classic and quantum computing. As a result, the timeline for achieving quantum supremacy seems to have shifted: RSA-2048 could very well be broken within a few years.

It’s also important to remember the concept of HNDL — “harvest now, decrypt later” (or SNDL — “store now, decrypt later”). Attackers with significant resources could already be collecting and storing data that can’t currently be decrypted. Once quantum computers with sufficient power become available, they’ll immediately begin retroactive decryption. Of course, when this fateful moment comes, it will already be too late, so quantum-resistant encryption standards should be implemented right now.

The ideal approach to deploying post-quantum cryptography based on established IT industry practices is hybrid encryption; that is, encrypting data in two layers: first with a classical algorithm, then with a post-quantum one. This forces attackers to contend with both cryptosystems — significantly lowering the chances of a successful breach. This approach is already being used by Signal, Apple, Google, and Zoom.

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At the time of writing, Pavel Durov has been charged in France, but hasn’t appeared in court yet. How things will pan out in court remains very unclear, but in the meantime scammers are already exploiting the massive attention and panic surrounding Telegram, while much dubious advice on social media is circulating regarding what to do now with the app. Our two-cents in a nutshell: Telegram users should remain calm, and act depending only on the facts as they currently stand. Now for what we can recommend today in detail…

Chat privacy and the “keys to Telegram”

Put simply, most chats on Telegram cannot be considered confidential — and this has always been the case. If you’ve been exchanging sensitive information on Telegram without using secret chats, consider it compromised. Move your private communications to another messenger following these recommendations.

Many news outlets suggest that the main complaint against Durov and Telegram is their refusal to cooperate with the French authorities and provide the “keys to Telegram”. Supposedly, Durov possesses some kind of cryptographic keys, which can be used to read users’ messages. In fact, few people really know how the Telegram server is structured, but from the available information, it is known that the bulk of correspondence is stored on servers in minimally encrypted form — that is, the decryption keys are stored within the same Telegram infrastructure. The creators claim that chats are stored in one country, while keys are stored in another, but considering that all the servers communicate with each other, it’s not clear how effective this security measure is in practice. It would help if the servers were confiscated in one country, but that’s about it. End-to-end encryption, which is standard in other messengers (WhatsApp, Signal and even Viber), is called “secret chat” in Telegram. It’s somewhat hidden in the depths of the interface and needs to be manually activated for selected personal chats. All group chats, channels, and standard personal correspondence lack end-to-end encryption and can be read at least on Telegram servers. Moreover, for both secret chats and everything else, Telegram uses its own non-standard protocol — MTProto — which has been found to contain serious cryptographic vulnerabilities. Therefore, Telegram correspondence can theoretically be read by:

Telegram server administrators
Hackers who’ve successfully breached Telegram servers and installed spyware
Third parties with some kind of access granted by Telegram administrators
A third party that has discovered cryptographic vulnerabilities in Telegram protocols and can read (selectively or in full) at least non-secret chats by intercepting the traffic of some users

Deleting correspondence

Some categories of users have been advised to delete old chats in Telegram, such as work-related ones. This advice seems questionable, because in databases (where correspondence is stored on the server), entries are rarely actually deleted; they’re simply marked as such. Moreover, like any major IT infrastructure, Telegram likely implements a robust data backup system, meaning “deleted” messages will be kept at least in database backups. It may be more effective for both chat participants (or group admins) to completely delete the chat. However, the issue of backups would still remain.

Backing up chats

A number of observers have expressed concerns that Telegram could be removed from app stores, blocked, or otherwise disrupted. While this seems unlikely, backing up important correspondence, photos and documents is still good practice in digital hygiene.

To save a backup of important personal correspondence, you need to install Telegram on your computer (official client here), log into your account, and then navigate to Settings → Advanced → Export Telegram data.

In the pop-up window, you can select the data you want to export (personal chats, group chats — with or without photos and videos), set download size limits, and choose the data format — HTML, which can be viewed in any browser, or JSON for automated processing by third-party apps.

Downloading the data to your computer could take several hours and may require dozens or even hundreds of gigabytes of free space, depending on how much you use Telegram and the export settings. You can close the export window, but be sure not to exit the app itself or disconnect your computer from the internet or the mains. We recommend only using the backup feature in the official client.

“Preventing Telegram’s deletion” from smartphones

First, let’s look at iOS. The folks at Cupertino don’t remove apps from users’ smartphones — even if apps are removed from the App Store, so any advice about stopping Telegram being deleted from iPhones is bogus. Moreover, a popular method for “Telegram deletion prevention” circulating online — that using the Screen Time menu — doesn’t prevent Apple from deleting apps; it only prevents certain users (e.g., children) from deleting apps themselves: as such it’s a parental control feature. And there’s more: Durov’s arrest has revived the old false claim about Telegram being removed remotely from iPhones, which both Apple and Telegram officially denied back in 2021.

As for Android, Google also doesn’t typically delete apps — except when it’s 100% malicious software. True, such guarantees don’t apply to all holders of other ecosystems (Samsung, Xiaomi and so on), but on Android it’s easy to install Telegram directly from the Telegram website.

Alternative clients

There are unofficial but still functional and legal clients for Telegram, and even an “official alternative client” — Telegram X. These clients all use the Telegram API, but it’s unclear whether they provide any additional benefits or increased security. The top five alternative clients on Google Play each talk about “improved security” – but only refer to features like hiding chats on a device.

Of course, you may end up downloading malware disguised as an alternative Telegram client — scammers don’t miss an opportunity to exploit the app’s popularity. If you’re considering alternative clients, follow these safety guidelines:

Download them only from official app stores.
Make sure the app has been around for a while, and has high ratings and a large number of downloads.
Use reliable antivirus protection across all platforms such as Kaspersky Premium.

Fundraising for Durov and defending free speech

This isn’t directly related to Telegram chats, but it’s important to beware also of scammers posing as those raising funds for Pavel Durov’s legal defense (like, he really needs the cash), while actually aiming to steal payment information or cryptocurrency donations. Treat such requests with extreme suspicion, and verify whether the alleged organization really exists and really is conducting such a campaign. For more on charity scams, check out our dedicated article.

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The aggressive introduction of AI in Microsoft products, geopolitical tensions, and a series of cybersecurity incidents involving the Redmond giant are pushing many organizations worldwide to switch to open-source alternatives to Windows and Office. To replace the latter, both OpenOffice and its offshoot LibreOffice are very popular. They’re available on all major platforms — including Linux, offer functionality comparable to MS Office, and come with the licenses suitable for large companies.

Due to their similarity to MS Office, the risks associated with using these suites are also similar: software vulnerabilities or unsecure settings can result in the execution of malicious code on the computer, or stealthily redirect the user to phishing links. And these threats aren’t mere theory — malicious documents in .odt files and other “open” document formats have been encountered in the wild. To mitigate these risks, the German Federal Office for Information Security (BSI) has issued public recommendations for secure LibreOffice settings. Let’s look together at the most important ones when using LibreOffice in organizations.

Configuration tips

The tips below apply to safe setup of LibreOffice on Linux, MacOS, or Windows in a managed corporate environment (through group policies and other centralized control tools). The tips concern the Writer, Calc, Impress, Base, Math, and Draw components of version 7.2.x. The recommended settings are based on the following considerations:

The end user should make the fewest possible decisions affecting security.
The functionality of the application should not be significantly reduced.
Unnecessary features should be deactivated to reduce the attack surface.
Whenever possible, transfer of data from the product to the manufacturer should be disabled.
External cloud services should be avoided unless they’re necessary for the organization’s business processes.

Configuration storage

LibreOffice settings can be modified by the administrator or by the user. Initial administrative settings are stored in the LibreOffice folder. On all platforms, the settings are applied as XML files (settings.xml), but they can also be stored in platform-specific formats (registry in Windows, dconf in Linux). For medium and large organizations, XML is recommended.

If a setting shouldn’t be modified by users, it can be marked as finalized in the administrator settings.
For example, below is a settings snippet that disables saving the document-author information (the RemovePersonalInfoOnSaving setting in the group org.openoffice.Office.Common/Security/Scripting) and prohibits changing this setting:

<item oor:path=”/org.openoffice.Office.Common/Security/Scripting”>
<prop about:name=”RemovePersonalInfoOnSaving” about:finalized=”false” about:op=”fuse” oor:type=”xs:boolean”>
<value>true</value>
</prop>
</item>

Folders for administrative settings (in version 7.2) are listed below:

Linux: /opt/libreoffice7.2/share/registry/res
MacOS: /Applications/LibreOffice.app/Contents/Resources/registry/res
Windows: C:Program FilesLibreOfficeshareregistryres

Settings to change

Many of LibreOffice’s settings are secure by default. Here, we’ll focus on those that need to be tightened.

Macro execution

By default, any signed macros are executed, so this setting must be tightened to the max — allowing only macros from trusted folders to be executed. So in the group org.openoffice.Office.Common/Security/Scripting, set the MacroSecurityLevel to 3:

<prop over:name=”MacroSecurityLevel” over:finalized=”true” over:op=”fuse” over:type=”xs:int”>
<value>3</value>
</prop>

To disable macros entirely, set the DisableMacrosExecution option from the same group to true with the finalized tag.

Trusted folders

By default, LibreOffice updates the list of trusted folders based on user activity — often including folders like Downloads. To clearly set trusted document storage locations, list them in the SecureURL option. The list can be left empty.

<item oor:path=”/org.openoffice.Office.Common/Security/Scripting ear:type=”oor:string-list”>
<plug about:name=”SecureURL” about:finalized=”true” about:op=”fuse”/>
</item>

Loading external images

Images from external sources can be embedded into documents. This creates significant risks of phishing and vulnerability exploitation, so this option should be disabled: set BlockUntrustedRefererLinks to true with the finalized tag in the /org.openoffice.Office.Common/Security/Scripting group.

Updating linked data

Linked content loaded in Calc can also be malicious, so updates should be blocked by setting the Link option to 1+finalized in the /org.openoffice.Office.Calc/Content/Update group.

The corresponding setting in Writer has different numeric values for some reason; block it by setting Link to 0+finalized in /org.openoffice.Office.Writer/Content/Update.

Exotic files

To disable loading of Abiword, Hangul Office, StarOffice XML, and other irrelevant formats, set LoadExoticFileFormats to 0 in the /org.openoffice.Office.Common/Security group.

Additionally, any of the 100+ supported file formats can be blocked by setting the Enabled option to false+finalized for any format in the group
/org.openoffice.TypeDetection.Filter/Filters/org.openoffice.TypeDetection.Filter:Filter[‘NAME’].
Replace NAME with the name of the format to be blocked.

System authentication

LibreOffice applications can automatically access external URLs using the credentials of the current user, potentially leading to credential leakage. To disable this behavior, set an empty list in the AuthenticateUsingSystemCredentials option:

<item oor:path=”/org.openoffice.Office.Common/Passwords”>
<prop oor:name=”AuthenticateUsingSystemCredentials” oor:finalized=”true” over:op=”fuse” ear:type=”oor:string-list”/>
</item>

Installing extensions

It’s recommended to disable user installation of extensions and allow extensions to be added only centrally through administrator privileges: set DisableExtensionInstallation to true+finalized in the /org.openoffice.Office.ExtensionManager/ExtensionSecurity group.

To centralize the removal of extensions and disable the ability to do this manually by the user, set DisableExtensionRemoval to true+finalized in the same group.

Updates

LibreOffice applications automatically check for updates, and prompt the user to install them. If updates and patches are managed centrally within the organization, this option can be disabled by setting AutoCheckEnabled to false+finalized in the /org.openoffice.Office.Jobs/Jobs/org.openoffice.Office.Jobs:Job[‘UpdateCheck’]/Arguments group.

Installation of fonts, language packs, and databases (Linux only)

Although these additions may seem harmless, for security reasons, automatic installation should be disabled. Set the EnableFontInstallation, EnableLangpackInstallation, and EnableBaseInstallation options to false+finalized in the /org.openoffice.Office.Common/PackageKit group.

Disable telemetry

Set the CollectUsageInformation and CrashReport options to false+finalized in the /org.openoffice.Office.Common/Misc group.

Document-signing certificates (Linux only)

By default, any folder can be chosen for the NSS database, which stores certificates. This isn’t secure and can lead to certificate leaks from uncontrolled locations. The administrator should specify a storage location designated by the organization using the CertDir option:

<item oor:path=”/org.openoffice.Office.Common/Security/Scripting”>
<prop over:name=”CertDir” over:op=”fuse” over:type=”xs:string”/>
</item>

Removing personal data (document author data)

If document distribution cannot be controlled, author data often needs to be hidden. To make LibreOffice remove this data when saving a document, add the RemovePersonalInfoOnSaving setting (true+finalized) in the /org.openoffice.Office.Common/Security/Scripting group.

This mode makes it more complicated to collaborate on a document as it’s harder to identify the author of any changes, so it’s not suitable for all organizational roles.

BSI also recommends disabling the saving of full PGP keys in signed documents, as they also contain author’s personal data: set MinimalKeyExport to true+finalized in the /org.openoffice.Office.Common/Security/OpenPGP group.

Settings to lock

These settings are initially set to be secure, but should be prevented from being changed by adding the finalized attribute.

Group name
Setting name
Value

/org.openoffice.Inet/Settings
ooInetProxyType
1

/org.openoffice.Office.Common/Security/Scripting
HyperlinksWithCtrlClick
true

/org.openoffice.Office.Security/Hyperlinks
Open
1

/org.openoffice.Office.Common/Security/Scripting
CheckDocumentEvents
true

/org.openoffice.Office.Common/Passwords
UseStorage
False

/org.openoffice.Office.Common/Passwords
TrySystemCredentialsFirst
false

/org.openoffice.Office.Jobs/Jobs/org.openoffice.Office.Jobs:Job[‘UpdateCheck’]/Arguments
ExtendedUserAgent
false

 

Additional protective layers

On any platform, users may encounter targeted cyberattacks and malicious documents. Therefore, secure OS and office suite settings should be complemented by a comprehensive set of layered defense measures:

Multi-factor authentication
Centralized access rights management
Mandatory EDR agent on all workstations and servers
Centralized security event monitoring using SIEM, or preferably XDR solutions.

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