3 ms·

Can someone smarter than me clarify if this also means a single 4090 can crack it in about 160 hours? Or are there a lot of other efficiencies gained by adding

by pc86 2y ago

Can someone smarter than me clarify if this also means a single 4090 can crack it in about 160 hours? Or are there a lot of other efficiencies gained by adding multiple GPUs together?

ffhhj 2y ago
Or 160 cards take 1 hour?
- bayindirh 2y ago
  More like 2, probably. If you have the lanes, of course. =]
bayindirh 2y ago
From my educated guess, A single 4090 can crack it around ~140, since there will be some scaling losses. Also, this is an optimistic take since we don't expect the VRAM won't have any bit-flip events during this time, under load. If you can have 10 Tesla cards, the number will be a bit shorter (around 14, I guess), since NVLink is much more efficient and creates a mesh between cards without hitting the PCIe.
- patates 2y ago
  Remembering the good old days when you could use it to connect consumer cards...
  - rtkwe 2y ago
    The advantages from SLI were always well below doubling and usually more like 50%. As frame rates and everything else has gotten higher and more complex the overhead of SLI got more and more onerous to the point where it barely gave much of an advantage to support at all.
- fwip 2y ago
  Doesn't have any scaling losses - it's a very parallel problem. Divide the keyspace N ways, run N brute-force searches. Similarly, it doesn't benefit from a faster connection to other nodes or main memory. Most bit-flips won't matter - either you get a false positive which is ruled out trivially, or the 1-in-$SearchSpace chance you get the false negative.
  - jerf 2y ago
    For education's sake and better internet search terms, there's some terms for this, the most popular of which is "embarassingly parallel": https://en.wikipedia.org/wiki/Embarrassingly_parallel https://en.wikipedia.org/wiki/Embarrassingly_parallel And agreed; coordination costs are negligible next to the cost of the calculation, so it should be effectively linear, and dominated by the luck of the draw on when the correct key is selected.
splix 2y ago
Seems so. Article initially says that it takes ~7 days (168 hours) to decrypt on a single card, but later suggests to use multiple.
speerer 2y ago
Actually, the result that's being announced is exactly this parallel property.From the article: > "With an RTX 4090, the Tinyhack found they could crack the encrypted ransomware'd files in seven days, and with 16 GPUs, the process would take just over ten hours." (and 160h ≈ 7 days)

by pc86 2y ago

Can someone smarter than me clarify if this also means a single 4090 can crack it in about 160 hours? Or are there a lot of other efficiencies gained by adding multiple GPUs together?

ffhhj 2y ago

Or 160 cards take 1 hour?

bayindirh 2y ago
More like 2, probably. If you have the lanes, of course. =]

bayindirh 2y ago

From my educated guess, A single 4090 can crack it around ~140, since there will be some scaling losses. Also, this is an optimistic take since we don't expect the VRAM won't have any bit-flip events during this time, under load. If you can have 10 Tesla cards, the number will be a bit shorter (around 14, I guess), since NVLink is much more efficient and creates a mesh between cards without hitting the PCIe.

patates 2y ago
Remembering the good old days when you could use it to connect consumer cards...
- rtkwe 2y ago
  The advantages from SLI were always well below doubling and usually more like 50%. As frame rates and everything else has gotten higher and more complex the overhead of SLI got more and more onerous to the point where it barely gave much of an advantage to support at all.
fwip 2y ago
Doesn't have any scaling losses - it's a very parallel problem. Divide the keyspace N ways, run N brute-force searches. Similarly, it doesn't benefit from a faster connection to other nodes or main memory. Most bit-flips won't matter - either you get a false positive which is ruled out trivially, or the 1-in-$SearchSpace chance you get the false negative.
- jerf 2y ago
  For education's sake and better internet search terms, there's some terms for this, the most popular of which is "embarassingly parallel": https://en.wikipedia.org/wiki/Embarrassingly_parallel https://en.wikipedia.org/wiki/Embarrassingly_parallel And agreed; coordination costs are negligible next to the cost of the calculation, so it should be effectively linear, and dominated by the luck of the draw on when the correct key is selected.

splix 2y ago

Seems so. Article initially says that it takes ~7 days (168 hours) to decrypt on a single card, but later suggests to use multiple.

speerer 2y ago

Actually, the result that's being announced is exactly this parallel property.From the article: > "With an RTX 4090, the Tinyhack found they could crack the encrypted ransomware'd files in seven days, and with 16 GPUs, the process would take just over ten hours." (and 160h ≈ 7 days)