4 ms·
Previous discussion (previous GitHub repository seems to have been deleted): https://news.ycombinator.com/item?id=5340181 https://news.ycombinator.com/item?id=5
by johndough 5y ago
Previous discussion (previous GitHub repository seems to have been deleted): https://news.ycombinator.com/item?id=5340181 https://news.ycombinator.com/item?id=5340181
The title should probably contain a reference to the year since it has last been updated (2012).
I'd like to point out that the following statement from the cheat sheet is incorrect:
# Checksum a file (safer algorithm with no hash collisions):
sha1sum
Since there are only 2^160 possible SHA-1 checksums, but an infinite number of possible documents, there MUST be an infinite number of documents that map to the same SHA-1 checksum due to the pigeonhole principle.
Examples for such documents have been found since the original cheat sheet has been published: https://shattered.io/ https://shattered.io/ It is now trivial to produce an arbitrary number of documents with hash collisions, although it is not trivial (yet?) to find a second document which has the same checksum as a specific document.