I've been considering writing a couple of checksum-based challenges, and while checking for duplicates, I noticed that both and exist.

Now, hashing and checksums aren't the same thing, but people seem to be using them fairly interchangeably, and they're certainly related in spirit. There are three solutions I can think of (and maybe other solutions that people will think of in the answers):

  1. Ensure that the tags have no overlap, going through all questions that use either and making sure the tag is appropriate;
  2. Make the tags into synonyms, and use them interchangeably from then on;
  3. Make one of the tags into a subset of the other (so all challenges about checksums or hashing will have one of the tags in particular, and a subset will have both).

Which of these options will lead to the best categorisations of these sorts of questions?

  • \$\begingroup\$ I apologise for the awkward wording of the title; SE doesn't let you start a question with a square bracket. \$\endgroup\$
    – user62131
    Jan 2, 2017 at 14:05
  • \$\begingroup\$ I'm guessing somebody has been doing some cleanup: I only see two questions tagged checksum, and neither of them are tagged hashing \$\endgroup\$ Jan 2, 2017 at 16:31
  • \$\begingroup\$ But isn't comparing hashing and checksums like comparing apples and oranges. Actually, more like fruit and apples not that I think about it.. \$\endgroup\$
    – ThreeFx
    Jan 3, 2017 at 2:04
  • \$\begingroup\$ He mentioned that: "Now, hashing and checksums aren't the same thing, but people seem to be using them fairly interchangeably, and they're certainly related in spirit" \$\endgroup\$ Jan 3, 2017 at 4:27
  • \$\begingroup\$ Full disclosure: I updated the tag wiki (actually, created: it didn't previously have one) for hashing to match how the tag's being used in practice, and thus explicitly listing checksum problems as a valid use for the tag. If people disagree with that, it may need to be re-edited. \$\endgroup\$
    – user62131
    Jan 5, 2017 at 8:40

1 Answer 1


Make a synonym for

Although hashing and checksums aren't the same thing, a checksum can certainly be seen as a sort of simple hashing algorithm. As such, isn't inappropriate for a checksum-based problem, even though it's vaguer than it could be. (If this solution is adopted, I'd change its tag wiki to clarify that it covers both cryptographic and non-cryptographic hash functions.) The tag is only sparsely used right now, and I'm not sure we would have a huge advantage to the uses of hashes in cryptography from the uses in checking for corruption (not to mention that there's a third common use of hashes on PPCG which doesn't fall nearly into either category, , but this tends to be a property of the answers rather than the questions).

As such, the best technical solution is probably to set up a tag synonym (i.e. a redirect) from to ; that way, anyone who tried to use on a challenge or in the search box would get instead. If this answer is well-received, I'll officially propose the synonym.


You must log in to answer this question.