this post was submitted on 31 Jan 2024
652 points (97.9% liked)

Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

55789 readers
232 users here now

⚓ Dedicated to the discussion of digital piracy, including ethical problems and legal advancements.

Rules • Full Version

1. Posts must be related to the discussion of digital piracy

2. Don't request invites, trade, sell, or self-promote

3. Don't request or link to specific pirated titles, including DMs

4. Don't submit low-quality posts, be entitled, or harass others



Loot, Pillage, & Plunder

📜 c/Piracy Wiki (Community Edition):


💰 Please help cover server costs.

Ko-Fi Liberapay
Ko-fi Liberapay

founded 2 years ago
MODERATORS
 
you are viewing a single comment's thread
view the rest of the comments
[–] mindbleach@sh.itjust.works 59 points 1 year ago (5 children)

I've done the math for how long it'd take to randomly guess the last several kilobytes until something checksummed correctly.

I was not pleased with the answer.

[–] holycrap@lemm.ee 26 points 1 year ago

That would put those crypto miners to better use at least

[–] Catsrules@lemmy.ml 14 points 1 year ago

You know I never thought of that.. but yeah that would be a good very very very very large number.

Like throwing puzzle pieces in the air and getting it to land completed.

[–] 0x0@lemmy.dbzer0.com 9 points 1 year ago (1 children)

On average it'll take 2^(n-1) guesses to reconstruct 2^n bits, so... depends on how many hashes / sec you can do.

[–] mindbleach@sh.itjust.works 15 points 1 year ago (1 children)

Let me save you some time: not enough.

[–] 0x0@lemmy.dbzer0.com 4 points 1 year ago

Haha agreed, if we're talking about kilobytes of missing data brute forcing is intractable.

There may be structure to exploit in the data format. E.g. if you're recovering missing content from a book written in English, you can probably get away with enumerating only printable ASCII and 90% of the letters will be lowercase.

But practically, I am unconvinced because the information density is pretty high on the kinds of things people like to torrent.

[–] urfavlaura@lemmy.ml 4 points 1 year ago

wait until you hear about collisions (missing more bits than your hash output length guarantees a collision on average)

If its a piece at the beggining or end of the file it would likely be significantly easier