Proton AG

Key takeaways

Proton AG belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Proton AG to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Proton AG from memory before moving on to harder problems.

Reference excerpt

Proton AG is a Swiss for-profit technology company offering privacy-focused online services and software. It is majority owned by the non-profit Proton Foundation as a shareholder. The company was formerly known as Proton Technologies.

Products

Proton Mail

Proton Mail was released as a public beta on 16 May 2014 as an end-to-end encrypted email service after a year of crowdfunding. Proton Mail 2.0 was released on 14 August 2015, with open-source front-end clients and a rewritten codebase.

Proton VPN

After over a year of crowdfunding, Proton Mail released Proton VPN on 22 May 2017, a secure VPN service provider. It has a no-logging policy, DNS and WebRTC IP address leakage prevention. It is accessible online through Tor, the clearnet, and its mobile applications. On 21 January 2020, Proton announced that Proton VPN would now be open source, to allow independent security experts to analyze it, becoming the first VPN service to do so, simultaneously announcing that an independent security audit had been conducted. On 1 May 2020, Proton VPN reported that they had a total of 809 servers, located in 50 different countries, all owned and operated by the company. By 19 February 2025, the company had a total of 11,496 servers, located in 117 countries, with all new and preexisting servers operated and owned by Proton.

Proton Calendar

Proton Calendar is an online end-to-end encrypted calendar native app and website.

Standard Notes Standard Notes is an end-to-end encrypted note-taking application, which was announced to be acquired by Proton on 10 April 2024.

Proton Drive

Proton Drive is a cloud storage solution with end-to-end encryption, launched in September 2022 after being in beta testing since 2020. On 3 July 2024, Proton launched Proton Docs for editing documents in Proton Drive in collaboration with the Standard Notes team. On 4 December 2025, they added spreadsheet support with Proton Sheets.

Lumo AI

In July 2025, Proton launched Lumo, an AI chatbot that stores chat logs in encrypted storage. Proton stated that user data in Lumo is not used to train AI models. Lumo can search the internet using “privacy-friendly” search engines, and can analyse user uploaded or Proton Drive files. Lumo is operated from German and Norwegian data centres.

SimpleLogin

SimpleLogin is an open-source email alias service that allows users to use email aliases to protect their main inbox from spam and phishing attacks. SimpleLogin also provides additional security features such as PGP encryption and two-factor authentication on various platforms including the web, mobile apps and browser extensions. After being acquired by Proton in early 2022, SimpleLogin functionality was integrated into Proton Mail, Proton Pass, and the rest of the Proton ecosystem.

Proton Pass

Released in public beta on 20 April 2023, Proton Pass is a cloud-based password manager solution with end-to-end encryption. As of 28 June 2023, it is available to all Proton users. It also allows users to generate email aliases through SimpleLogin.

Proton Wallet Proton Wallet is an open-source Bitcoin wallet with end-to-end encryption. The company claims the function to be "self-custodial" where users own their secret keys.

Proton Authenticator Proton Authenticator is an open-source and end-to-end encrypted software-based authenticator. When logging into a website or application that supports multi-factor authentication, the user will be prompted for a six-digit one-time password which changes every 30 seconds.

Proton Meet Proton Meet is an end-to-end encrypted video calling application launched on 4 September 2025. It was built using LiveKit and launched for public access on 31 March 2026.

Data centers Proton maintains and owns its own server hardware and network in order to avoid utilizing third parties. It maintains two data centers, one in Lausanne and another in Attinghausen (in the former K7 military bunker under 1,000 meters (3,300 ft) of granite rock) as a backup. Each data center uses load balancing across web, mail, and SQL servers, redundant power supply, hard drives with full disk encryption, and exclusive use of Linux and other open-source software. In December 2014, Proton joined the RIPE NCC in an effort to have more direct control over the surrounding Internet infrastructure. As of December 2024, Proton operates data centers in Switzerland, Germany, and Norway.

Structure Proton is headquartered in Plan-les-Ouates, Geneva, Switzerland.

Ownership Since June 2024, the controlling shareholder of Proton AG is the non-profit Proton Foundation. The members of the Proton Foundation board of trustees in June 2024 were Andy Yen, Antonio Gambardella, Carissa Véliz, Tim Berners-Lee and Dingchao Lu.

Funding Proton AG was initially funded through crowdfunding and now through paid subscriptions. The company has been partially funded by FONGIT (the Fondation Genevoise pour l'Innovation Technologique) and the European Commission. In March 2021, Proton confirmed that the shares held by Charles Rivers Ventures had been transferred to FONGIT.

Acquisitions On 8 April 2022, Proton acquired French email aliasing startup SimpleLogin. Proton has stated SimpleLogin will continue to function as a standalone service and the SimpleLogin team will continue to add new features and functionality. On 12 April 2024, Proton acquired note taking app Standard Notes.

… excerpt ends here. Continue reading the full article.

Illustrations

SimpleLogin logo

Worked examples

Example 1 — a first encounter with Proton AG

Start with the simplest possible case. Write down what Proton AG claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Proton AG before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Proton AG ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Proton AG

In research: Proton AG appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Proton AG in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Proton AG is common in secondary-school and first-year university syllabi. It links to neighbouring topics Companies based in Geneva, Proton AG, Software companies established in 2014, so understanding it makes those chapters shorter.
In everyday life: Look for Proton AG outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Proton AG in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Proton AG means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Proton AG out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Proton AG in simple terms?

Proton AG is a Swiss for-profit technology company offering privacy-focused online services and software. It is majority owned by the non-profit Proton Foundation as a shareholder.

Why does Proton AG matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Proton AG?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Proton AG.