this post was submitted on 04 Jul 2023
3087 points (95.7% liked)
You Should Know
33167 readers
131 users here now
YSK - for all the things that can make your life easier!
The rules for posting and commenting, besides the rules defined here for lemmy.world, are as follows:
Rules (interactive)
Rule 1- All posts must begin with YSK.
All posts must begin with YSK. If you're a Mastodon user, then include YSK after @youshouldknow. This is a community to share tips and tricks that will help you improve your life.
Rule 2- Your post body text must include the reason "Why" YSK:
**In your post's text body, you must include the reason "Why" YSK: It’s helpful for readability, and informs readers about the importance of the content.
**
Rule 3- Do not seek mental, medical and professional help here.
Do not seek mental, medical and professional help here. Breaking this rule will not get you or your post removed, but it will put you at risk, and possibly in danger.
Rule 4- No self promotion or upvote-farming of any kind.
That's it.
Rule 5- No baiting or sealioning or promoting an agenda.
Posts and comments which, instead of being of an innocuous nature, are specifically intended (based on reports and in the opinion of our crack moderation team) to bait users into ideological wars on charged political topics will be removed and the authors warned - or banned - depending on severity.
Rule 6- Regarding non-YSK posts.
Provided it is about the community itself, you may post non-YSK posts using the [META] tag on your post title.
Rule 7- You can't harass or disturb other members.
If you harass or discriminate against any individual member, you will be removed.
If you are a member, sympathizer or a resemblant of a movement that is known to largely hate, mock, discriminate against, and/or want to take lives of a group of people and you were provably vocal about your hate, then you will be banned on sight.
For further explanation, clarification and feedback about this rule, you may follow this link.
Rule 8- All comments should try to stay relevant to their parent content.
Rule 9- Reposts from other platforms are not allowed.
Let everyone have their own content.
Rule 10- The majority of bots aren't allowed to participate here.
Unless included in our Whitelist for Bots, your bot will not be allowed to participate in this community. To have your bot whitelisted, please contact the moderators for a short review.
Partnered Communities:
You can view our partnered communities list by following this link. To partner with our community and be included, you are free to message the moderators or comment on a pinned post.
Community Moderation
For inquiry on becoming a moderator of this community, you may comment on the pinned post of the time, or simply shoot a message to the current moderators.
Credits
Our icon(masterpiece) was made by @clen15!
founded 1 year ago
MODERATORS
That's the point of a hash function. You have a public hash function, say SHA-256. It's easy to check a username against it's hash, but virtually impossible to reverse the hash back to the username.
Edit: Instead of storing, say,
eddie, we'd store3b9d8298f1b5086d012618feebb2da1a394357c1dab7523443c9f6a743c4c84d. Then when the instance gets aLikefromeddie, it hashes his username to get3b9d8298f1b5086d012618feebb2da1a394357c1dab7523443c9f6a743c4c84d, realizes there's a match, and doesn't update the count.Note that when given
3b9d8298f1b5086d012618feebb2da1a394357c1dab7523443c9f6a743c4c84d, it would take millions of CPU years to compute the original username from it. Therefore, we can check for duplicates without actually checking the name itself (a similar method is used for checking passwords; Lemmy is open source, we know the hashing algorithm, but we can't unhash user passwords, only check them).While there is an enormous amount of possible passwords, there is only a limited (and quite small) amount of users. Couldn't you just hash all the usernames one by one and map the hashes to the usernames? So you could still reverse engineer the usernames of those who voted on a post.
Edit: Salting with the post id would make this attacking process harder, but still realistic. Probably the only real solution is to hide the votes table from federated instances, I'm not sure if that brings technical problems.
If anything, wouldn't that make vote abuse even easier? Just send 100 upvotes with 100 random hashes.
That was what I was implying, yes.
Just hash each username and store it. Then just check the usernames hash to see if it matches.
I was more comnenting that you could still reverse engineer the users who voted on a post
Actually, you’re not really wrong.
All the more reason to give out limited data to all other instances. Why do these instances really need this data? Mastodon doesn’t need it, not quite sure why Lemmy does it.
Yeah I don't understand why every instance can't keep track of their own votes privately. Sure, voting manipulation is a thing, but it's possible regardless.
Honestly I really hope Lemmy does something to address this issue. Otherwise it's kind of a dealbreaker for me.