computer science

Whisper Systems

Whisper Systems 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 Whisper Systems rather than just read about it. In short: Whisper Systems was an American enterprise mobile security company that was co-founded by security researcher Moxie Marlinspike and roboticist Stuart Anderson in 2010. The company was acquired by Twitter in November 2011.

Key takeaways

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

Reference excerpt

Whisper Systems was an American enterprise mobile security company that was co-founded by security researcher Moxie Marlinspike and roboticist Stuart Anderson in 2010. The company was acquired by Twitter in November 2011. Some of the company's software products were released under open-source licenses after the acquisition. An independent group called Open Whisper Systems later picked up the development of this open-source software, which led to the creation of the Signal Technology Foundation.

History Security researcher Moxie Marlinspike and roboticist Stuart Anderson co-founded Whisper Systems in 2010. The company produced proprietary enterprise mobile security software. Among these were an encrypted texting program called TextSecure and an encrypted voice calling app called RedPhone. They also developed a firewall and tools for encrypting other forms of data. On November 28, 2011, Whisper Systems announced that it had been acquired by Twitter. The financial terms of the deal were not disclosed by either company. The acquisition was done "primarily so that Mr. Marlinspike could help the then-startup improve its security". Shortly after the acquisition, Whisper Systems' RedPhone service was made unavailable. Some criticized the removal, arguing that the software was "specifically targeted [to help] people under repressive regimes" and that it left people like the Egyptians in "a dangerous position" during the events of the 2011 Egyptian revolution. Twitter released TextSecure as free and open-source software under the GPLv3 license in December 2011. RedPhone was also released under the same license in July 2012. Marlinspike later left Twitter and founded Open Whisper Systems as a collaborative Open Source project for the continued development of TextSecure and RedPhone. Open Whisper Systems consisted of a large community of volunteer Open Source contributors, as well as a small team of dedicated grant-funded developers. In November 2015, Open Whisper Systems merged TextSecure with RedPhone and renamed it as Signal. In 2018, Signal Messenger was incorporated as an LLC by Moxie Marlinspike and Brian Acton and then rolled under the independent non-profit Signal Technology Foundation. Today, the Signal app is developed by Signal Messenger LLC, which is funded by the Signal Foundation. The foundation has stated publicly that they are not tied to any major technology companies and "can never be acquired by one either."

Products Whisper Systems' products were all made for Android and included:

TextSecure: An app that allowed the user to exchange end-to-end encrypted SMS messages with other TextSecure users. RedPhone: An app that allowed the user to make end-to-end encrypted VoIP calls to other RedPhone users. Flashback: An app that allowed the user to store encrypted backups of their device in the cloud. WhisperCore: An app that integrated with the underlying Android OS to protect everything the user kept on their phone. The initial beta featured full disk encryption, network security tools, encrypted backup, selective permissions, and basic platform management tools for Nexus S and Nexus One phones. WhisperMonitor: An app that worked with WhisperCore to provide a software firewall capable of dynamic egress filtering and real-time connection monitoring, giving the user control over where their data was going and what their apps were doing.

See also List of mergers and acquisitions by Twitter

References

External links Whisper Systems at the Wayback Machine (archived 17 January 2013)

Worked examples

Example 1 — a first encounter with Whisper Systems

Start with the simplest possible case. Write down what Whisper Systems 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 Whisper Systems 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 Whisper Systems 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 Whisper Systems

In research: Whisper Systems 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 Whisper Systems 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: Whisper Systems is common in secondary-school and first-year university syllabi. It links to neighbouring topics 2010 establishments in California, 2011 disestablishments in California, 2011 mergers and acquisitions, so understanding it makes those chapters shorter.
In everyday life: Look for Whisper Systems 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.

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How to study Whisper Systems in 20 minutes

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

Frequently asked questions

What is Whisper Systems in simple terms?

Why does Whisper Systems 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 Whisper Systems?

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 Whisper Systems.