Lesson plan

RC4

In cryptography, RC4 (also known as ARC4 or ARCFOUR, meaning Alleged RC4, see below) is a stream cipher. While it is remarkable for its simplicity and speed in software, multiple vulnerabilities have been discovered in RC4, rendering it insecure. It is especially vulnerable when the beginning of the output keystream is not discarded, or when nonrandom or related keys are used. Particularly problematic uses of RC4 have led to insecure protocols such as the obsolete WEP protocol historically used to secure WiFi networks. There has long been speculation that some state cryptologic agencies may possess the capability to break RC4 when used in the TLS protocol. In response, the IETF published to prohibit the use of RC4 in TLS; Mozilla and Microsoft have issued similar recommendations. A number of attempts have been made to strengthen RC4, notably Spritz, RC4A, VMPC, and RC4 + .

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Article summary

In cryptography, RC4 (also known as ARC4 or ARCFOUR, meaning Alleged RC4, see below) is a stream cipher. While it is remarkable for its simplicity and speed in software, multiple vulnerabilities have been discovered in RC4, rendering it insecure. It is especially vulnerable when the beginning of the output keystream is not discarded, or when nonrandom or related keys are used. Particularly problematic uses of RC4 have led to insecure protocols such as the obsolete WEP protocol historically used to secure WiFi networks. There has long been speculation that some state cryptologic agencies may possess the capability to break RC4 when used in the TLS protocol. In response, the IETF published to prohibit the use of RC4 in TLS; Mozilla and Microsoft have issued similar recommendations. A number of attempts have been made to strengthen RC4, notably Spritz, RC4A, VMPC, and RC4 + .

Key claims

  1. publication date: 2015 — source: Wikipedia · confidence 0.95
  2. publication date: 2016 — source: Wikipedia · confidence 0.95
  3. release date: 2008 — source: Wikipedia · confidence 0.95
  4. release date: 2014 — source: Wikipedia · confidence 0.95

Discussion questions

  1. Summarise the article in your own words. Which single claim would you verify first, and why?
  2. The record states that the publication date is "2015". What evidence would count against this claim?
  3. The record states that the publication date is "2016". What evidence would count against this claim?
  4. The record states that the release date is "2008". What evidence would count against this claim?
  5. The record states that the release date is "2014". What evidence would count against this claim?
  6. Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
  7. If two sources disagreed about one of these facts, what would you need in order to trust one over the other?

Bibliography

  1. Wikipedia https://en.wikipedia.org/w/index.php?oldid=1372526049

Key claims and bibliography are generated from the same tracked claims and sources as the article page.