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> Limiting itself to reversible operations gives some mathematical niceties What are those niceties, why is a reversible operation desirable in this context?
by mshroyer 2y ago
> Limiting itself to reversible operations gives some mathematical niceties
What are those niceties, why is a reversible operation desirable in this context?
- tyingq 2y ago"One of the important properties of an integer hash function is that it maps its inputs to outputs 1:1. In other words, there are no collisions. If there’s a collision, then some outputs aren’t possible, and the function isn’t making efficient use of its entropy. This is actually a lot easier than it sounds. As long as every n-bit integer operation used in the hash function is reversible, then the hash function has this property. An operation is reversible if, given its output, you can unambiguously compute its input." https://nullprogram.com/blog/2018/07/31/ https://nullprogram.com/blog/2018/07/31/
- jwilk 2y agoThe blog post discussed on HN: 2018: https://news.ycombinator.com/item?id=17659672 https://news.ycombinator.com/item?id=17659672 (14 comments) 2021: https://news.ycombinator.com/item?id=29117783 https://news.ycombinator.com/item?id=29117783 (1 comment)