Lesson plan
Cryptographic hash function
) at work. A small change in the input (in the word "over") drastically changes the output (digest). This is called the avalanche effect. A cryptographic hash function (CHF) is a hash algorithm (a map of an arbitrary binary string to a binary string with a fixed size of n bits) that has special properties desirable for cryptographic applications. Hashing is a one-directional mathematical operation which is quick to calculate, yet hard to reverse. Common uses include password storage and digital signatures. Even a small change in the input results in a very different hash, meaning that it functions as an efficient and consistent way to check if two copies of data or software match. Typically, the operation works on a block of input data; the hash output is then hashed with the next block, creating a new hash reflecting everything to that point; this action is repeated until the hash reflects everything through the final block. More technically: * the probability of a particular n -bit output result (hash value) for a random input string ("message") is 2^{-n} (as for any good hash), so the hash value can be used as a representative of the message; * finding an input string that matches a given hash value (a pre-image) is infeasible, assuming all input strings are equally likely.…
Article summary
) at work. A small change in the input (in the word "over") drastically changes the output (digest). This is called the avalanche effect. A cryptographic hash function (CHF) is a hash algorithm (a map of an arbitrary binary string to a binary string with a fixed size of n bits) that has special properties desirable for cryptographic applications. Hashing is a one-directional mathematical operation which is quick to calculate, yet hard to reverse. Common uses include password storage and digital signatures. Even a small change in the input results in a very different hash, meaning that it functions as an efficient and consistent way to check if two copies of data or software match. Typically, the operation works on a block of input data; the hash output is then hashed with the next block, creating a new hash reflecting everything to that point; this action is repeated until the hash reflects everything through the final block. More technically: * the probability of a particular n -bit output result (hash value) for a random input string ("message") is 2^{-n} (as for any good hash), so the hash value can be used as a representative of the message; * finding an input string that matches a given hash value (a pre-image) is infeasible, assuming all input strings are equally likely.…
Key claims
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Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
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Key claims and bibliography are generated from the same tracked claims and sources as the article page.