3 ms·

2560 bits is stronger than 256 bits and the extra cost does not matter for a tool designed to encrypt files. See what I did here? Where do we stop?

mytailorisrich 4y ago
This is absurd. I am only comparing the two main options (more or less) for symmetric encryption: 128 or 256. Edited as not AES but you get the point taking into account that AES256 is the standard.
- tptacek 4y ago
  Age doesn't use AES.
loup-vaillant 4y ago
We stop before the key is big enough to requires the energy of our sun to crack, even if you have an ideal computer. 256-bit keys require more energy than a nova. 128 bits however is humanly achievable (35 years worth of peak Bitcoin mining), and as such perhaps a tad low in really high stakes scenarios (say highly classified stuff). We could chose something between 128 and 256, but they're nice powers of two, and we tend to like powers of two.
- upofadown 4y ago
  I got billions of years when I used the current bitcoin hashing rate for 128 bits. Are you assuming a birthday attack?
  - loup-vaillant 4y ago
    No, I just botched it and pretended 2^35 = 35. See these other comments for more details: https://news.ycombinator.com/item?id=34955855 https://news.ycombinator.com/item?id=34955855 https://news.ycombinator.com/item?id=34963094 https://news.ycombinator.com/item?id=34963094
- vbezhenar 4y ago
  To enumerate 128 bits in 35 years you would need to make 3e29 attempts per second. Current bitcoin miner can provide efficiency of 19 000 000 MH/J or 19e12 H/J. If we would assume bruteforcer can perform with the same efficiency, we would need 1.6e16 J/s = 16 000 TW. Current humanity energy output is something like 17 TW.
  - loup-vaillant 4y ago
    Yeah, botched my numbers, sorry. I saw that the hash rate of the current Bitcoin network went up to 2^93 hashes per year, and then I managed to pretend 2^128/2^93 = 35, instead of 2^35. With your numbers if humanity dedicated all its energy to brute forcing a 128/bit key for a year it would have a ~0.1% chance of finding it. I guess that's a pretty good argument that no one is going to even try it in the foreseeable future. See this cousin comment highlighting my error. that out: https://news.ycombinator.com/item?id=34955855 https://news.ycombinator.com/item?id=34955855

mytailorisrich 4y ago

This is absurd. I am only comparing the two main options (more or less) for symmetric encryption: 128 or 256. Edited as not AES but you get the point taking into account that AES256 is the standard.

tptacek 4y ago
Age doesn't use AES.

loup-vaillant 4y ago

We stop before the key is big enough to requires the energy of our sun to crack, even if you have an ideal computer. 256-bit keys require more energy than a nova. 128 bits however is humanly achievable (35 years worth of peak Bitcoin mining), and as such perhaps a tad low in really high stakes scenarios (say highly classified stuff). We could chose something between 128 and 256, but they're nice powers of two, and we tend to like powers of two.

upofadown 4y ago
I got billions of years when I used the current bitcoin hashing rate for 128 bits. Are you assuming a birthday attack?
- loup-vaillant 4y ago
  No, I just botched it and pretended 2^35 = 35. See these other comments for more details: https://news.ycombinator.com/item?id=34955855 https://news.ycombinator.com/item?id=34955855 https://news.ycombinator.com/item?id=34963094 https://news.ycombinator.com/item?id=34963094
vbezhenar 4y ago
To enumerate 128 bits in 35 years you would need to make 3e29 attempts per second. Current bitcoin miner can provide efficiency of 19 000 000 MH/J or 19e12 H/J. If we would assume bruteforcer can perform with the same efficiency, we would need 1.6e16 J/s = 16 000 TW. Current humanity energy output is something like 17 TW.
- loup-vaillant 4y ago
  Yeah, botched my numbers, sorry. I saw that the hash rate of the current Bitcoin network went up to 2^93 hashes per year, and then I managed to pretend 2^128/2^93 = 35, instead of 2^35. With your numbers if humanity dedicated all its energy to brute forcing a 128/bit key for a year it would have a ~0.1% chance of finding it. I guess that's a pretty good argument that no one is going to even try it in the foreseeable future. See this cousin comment highlighting my error. that out: https://news.ycombinator.com/item?id=34955855 https://news.ycombinator.com/item?id=34955855