computer science

William Cheswick

William Cheswick 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 William Cheswick rather than just read about it. In short: William R. "Bill" Cheswick (also known as "Ches") is a computer security and networking researcher. Education Cheswick graduated from Lawrenceville School in 1970 and received a B.S. in Fundamental Science in 1975 from Lehigh University.

Key takeaways

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

Reference excerpt

William R. "Bill" Cheswick (also known as "Ches") is a computer security and networking researcher.

Education Cheswick graduated from Lawrenceville School in 1970 and received a B.S. in Fundamental Science in 1975 from Lehigh University. While at Lehigh, working with Doug Price and Steve Lidie, Cheswick co-authored the Senator line-oriented text editor.

Career Cheswick's early career included contracting in Bethlehem, PA between 1975 and 1977. He was a Programmer for American Newspaper Publishers Association / Research Institute in Easton, PA between 1976 and 1977 and a Systems Programmer for Computer Sciences Corporation in Warminster, PA between 1977 and 1978. Following this, Cheswick joined Systems and Computer Technology Corporation where he served as a Systems Programmer and Consultant between 1978 and 1987. Much of Cheswick's early career was related to his expertise with Control Data Corporation (CDC) mainframes, their operating systems such as SCOPE and NOS, and the related COMPASS assembly language. Cheswick initially worked with CDC systems as a student at Lehigh University. Cheswick joined Bell Labs in 1987. Shortly thereafter, he and Steven M. Bellovin created one of the world's first network firewalls. The resulting research and papers lead to their publication of the seminal book Firewalls and Internet Security, one of the first to describe the architecture of a firewall in detail. Cheswick and Bellovin also created one of the world's first honeypots in the course of detecting and trapping an attempted intruder into their network. In 1998, Cheswick, still at Bell Labs (by then controlled by Lucent) started the Internet Mapping Project, assisted by Hal Burch. The research allowed large scale mapping of the internet for the first time, using tracerouting techniques to learn the connectivity graph of global networks. The work ultimately led to the founding in 2000 of a spinoff company, Lumeta, where Cheswick was a co-founder and held the title of Chief Scientist. He joined AT&T Shannon Lab in 2007, where he remained until 2012.

Hobbies, interests, and personal projects Cheswick currently lives in New Jersey with his wife. He has two children. His home is a farmhouse in Flemington, New Jersey, which is an electronic smart house, equipped with a voice synthesizer that reports relevant information, from mailbox status to evening stock news. Cheswick has developed a few interactive exhibits for science museums, including the Liberty Science Center in New Jersey. Cheswick also enjoys model rocketry, and lock picking (both electronic and physical). He is interested in developing better passwords as discussed in his article "Rethinking Passwords" (Communications of the ACM 56.2 (2013)). Cheswick has also been seeking permission from filmmakers to publish his visualizations of their movies.

References

External links William R. Cheswick's home page Biography Home page for "Firewalls and Internet Security"

Illustrations

Worked examples

Example 1 — a first encounter with William Cheswick

Start with the simplest possible case. Write down what William Cheswick 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 William Cheswick 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 William Cheswick 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 William Cheswick

In research: William Cheswick 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 William Cheswick 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: William Cheswick is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computer scientist stubs, Computer security specialists, Lawrenceville School alumni, so understanding it makes those chapters shorter.
In everyday life: Look for William Cheswick 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 William Cheswick in 20 minutes

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

Frequently asked questions

What is William Cheswick in simple terms?

William R. "Bill" Cheswick (also known as "Ches") is a computer security and networking researcher. Education Cheswick graduated from Lawrenceville School in 1970 and received a B.S. in Fundamental Science in 1975 from Lehigh University.

Why does William Cheswick 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 William Cheswick?

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 William Cheswick.