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Hail Mary Cloud

Hail Mary Cloud 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 Hail Mary Cloud rather than just read about it. In short: The Hail Mary Cloud was, or is, a password guessing botnet, which used a statistical equivalent to brute force password guessing. The botnet ran from possibly as early as 2005, and certainly from 2007 until 2012 and possibly later.

Key takeaways

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

Reference excerpt

The Hail Mary Cloud was, or is, a password guessing botnet, which used a statistical equivalent to brute force password guessing. The botnet ran from possibly as early as 2005, and certainly from 2007 until 2012 and possibly later. The botnet was named and documented by Peter N. M. Hansteen. The principle is that a botnet can try several thousands of more likely passwords against thousands of hosts, rather than millions of passwords against one host. Since the attacks were widely distributed, the frequency on a given server was low and was unlikely to trigger alarms. Moreover, the attacks come from different members of the botnet, thus decreasing the effectiveness of both IP based detection and blocking.

References

External links That grumpy BSD guy: The Hail Mary Cloud And The Lessons Learned

Worked examples

Example 1 — a first encounter with Hail Mary Cloud

Start with the simplest possible case. Write down what Hail Mary Cloud 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 Hail Mary Cloud 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 Hail Mary Cloud 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 Hail Mary Cloud

In research
Hail Mary Cloud 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 Hail Mary Cloud 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
Hail Mary Cloud is common in secondary-school and first-year university syllabi. It links to neighbouring topics Botnets, Distributed computing, Password cracking software, so understanding it makes those chapters shorter.
In everyday life
Look for Hail Mary Cloud 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 Hail Mary Cloud in 20 minutes

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

Frequently asked questions

What is Hail Mary Cloud in simple terms?

The Hail Mary Cloud was, or is, a password guessing botnet, which used a statistical equivalent to brute force password guessing. The botnet ran from possibly as early as 2005, and certainly from 2007 until 2012 and possibly later.

Why does Hail Mary Cloud 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 Hail Mary Cloud?

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 Hail Mary Cloud.

Tags

  • Botnets
  • Distributed computing
  • Password cracking software

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