computer science

Lsh

Lsh 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 Lsh rather than just read about it. In short: lsh is a copyleft implementation of the Secure Shell (SSH) protocol version 2, by the GNU Project including both server and client programs. Featuring Secure Remote Password protocol (SRP) as specified in secsh-srp besides, public-key authentication.

Key takeaways

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

Reference excerpt

lsh is a copyleft implementation of the Secure Shell (SSH) protocol version 2, by the GNU Project including both server and client programs. Featuring Secure Remote Password protocol (SRP) as specified in secsh-srp besides, public-key authentication. Kerberos is somewhat supported as well. Currently however for password verification only, not as a single sign-on (SSO) method. lsh was started from scratch and predates OpenSSH. Karim Yaghmour concluded in 2003 that lsh was "not fit for use" in production embedded Linux systems, because of its dependencies upon other software packages that have a multiplicity of further dependencies. The lsh package requires the GNU MP library, zlib, and liboop, the latter of which in turn requires GLib, which then requires pkg-config. Yaghmour further notes that lsh suffers from cross-compilation problems that it inherits from glib. "If ... your target isn't the same architecture as your host," he states, "LSH isn't a practical choice at this time." Debian provides packages of lsh as lsh-server, lsh-utils, lsh-doc and lsh-client.

Worked examples

Example 1 — a first encounter with Lsh

Start with the simplest possible case. Write down what Lsh 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 Lsh 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 Lsh 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 Lsh

In research: Lsh 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 Lsh 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: Lsh is common in secondary-school and first-year university syllabi. It links to neighbouring topics Free network-related software, Free security software, GNU Project software, so understanding it makes those chapters shorter.
In everyday life: Look for Lsh 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 Lsh in 20 minutes

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

Frequently asked questions

What is Lsh in simple terms?

Why does Lsh 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 Lsh?

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 Lsh.

Lsh