computer science

Proton Pass

Proton Pass is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Proton Pass rather than just read about it. In short: Proton Pass is a freemium password manager with open-source clients, developed by the Swiss software company Proton AG. Overview Proton Pass can store login credentials, email aliases, credit card data, passkeys, 2FA secret keys, files, and notes in virtual vaults that are encrypted using 256-bit AES-GCM.

Key takeaways

Proton Pass 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 Pass to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Proton Pass from memory before moving on to harder problems.

Reference excerpt

Proton Pass is a freemium password manager with open-source clients, developed by the Swiss software company Proton AG.

Overview Proton Pass can store login credentials, email aliases, credit card data, passkeys, 2FA secret keys, files, and notes in virtual vaults that are encrypted using 256-bit AES-GCM. Browser extensions are available for Chromium-based browsers (Chrome, Edge, Brave, etc.) and Firefox.

History Following Proton's acquisition of SimpleLogin, in April 2022, engineers from both companies worked on developing a password manager to release under the Proton brand. On April 20, 2023, Proton launched a beta version of Proton Pass to a limited audience of existing Proton customers. On 28 June 2023, Proton Pass was launched globally under a freemium model. Initially, it was available as a browser extension (Chromium-based browsers and Firefox) and as a mobile app (iPhone/iPad and Android). On 19 July 2023, Proton published the results of its security audit of Proton Pass mobile apps, browser extensions, and API, conducted by Cure53. At the same time, Proton released the source code for Proton Pass under the GNU General Public License v3.0. On 25 October 2023, Proton announced the addition of a sharing feature to Proton Pass, allowing users to share passwords and other sensitive information with other Proton Pass users, via end-to-end encryption. On 25 January 2024, Proton announced that paid users would have access to the Proton Sentinel high-security program, which is designed to identify and prevent account takeover attacks. On 7 February 2024, Proton Pass for Business was launched, with 24/7 business support, increased sharing limits, unlimited vaults and a dedicated admin panel. On 29 February 2024, Proton announced the launch of the Proton Pass Windows app. On 21 March 2024, support was added for passkeys. This feature was made available to both free and paid plans. On 22 April 2024, the Proton Pass Android app became available on F-Droid. On 6 May 2024, a collection of security features, dubbed Pass Monitor, was launched, which lets users monitor their leaked password, breached email addresses, and password strength warnings from outside sources, including the dark web. On 6 June 2024, the Proton Pass macOS and Linux desktop apps, and the Safari browser extension were launched. On 12 July 2024, Proton Pass launched a secure sharing feature for paid plans, which allows users to share credentials and other information with non-Proton Pass users. This is via shared links, which includes limits on the number of clicks and time duration for the link to expire (no longer functional after user set the setting of the shared link). On 8 August 2024, Proton Pass launched its Identities feature which allows for storing and auto-filling common data such as name, address and telephone phone number. It also introduced biometric authentication. On 9 October 2024, Proton Pass launched a family plan. In April 2025, Proton Pass added support for file attachments attached to individual entries within the password manager. On 25 Nov 2025, Proton Pass now has the ability to be streamlined via the terminal.

Reviews Proton Pass launched in 2023 to largely positive reviews, although its minimal feature set was criticized at the time. Writing for Privacy Journal, Brett Day felt that "[Proton Pass is] a little feature barren, but the tools it offers are of high quality". According to TechCrunch, it is a "solid password manager" despite not being as feature rich as 1Password or other programs, and PCMag stated, "While short on frills, Proton Pass does a perfectly capable job of managing your passwords." In January 2024, PCMag named Proton Pass "Best for no-frills" password manager. In 2024, TechRadar named Proton Pass the best password manager for privacy, stating that despite its fairly recent release, Proton was still working very hard on its security.

Security incidents

2025 DOM-based Extension Clickjacking Security researcher Marek Tóth presented a vulnerability in browser extensions of several password managers (including ProtonPass) at DEF CON 33 on August 9, 2025. In their default configurations, these extensions were shown to be exposed to a DOM-based extension clickjacking technique, allowing attackers to exfiltrate user data with just a single click. The affected password manager vendors were notified in April 2025. According to Tóth, ProtonPass version 1.31.6 addressed the issue.

Illustrations

Worked examples

Example 1 — a first encounter with Proton Pass

Start with the simplest possible case. Write down what Proton Pass 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 Pass 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 Pass 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 Pass

In research: Proton Pass 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 Pass 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 Pass is common in secondary-school and first-year university syllabi. It links to neighbouring topics 2023 software, Cross-platform free software, Free Firefox WebExtensions, so understanding it makes those chapters shorter.
In everyday life: Look for Proton Pass 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.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Proton Pass in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Proton Pass 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 Pass out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Proton Pass in simple terms?

Proton Pass is a freemium password manager with open-source clients, developed by the Swiss software company Proton AG. Overview Proton Pass can store login credentials, email aliases, credit card data, passkeys, 2FA secret keys, files, and notes in virtual vaults that are encrypted using 256-bit A…

Why does Proton Pass 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 Pass?

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 Pass.