Re: Is Dropbox a safe place keep my TrueCrypted BTC wallet backup?
PBKDF2-HMAC-SHA512 / AES: 95 kHash/s
PBKDF2-HMAC-RipeMD160 boot-mode / AES: 451 kHash/s
OK, RipeMD took 40 seconds, SHA512 is 5 times slower, so it will take 10 minutes. Let's guess it was a simple password, it would take much longer with a better SHA512 password. But then remember it was just two HD6990. Let's see what we can do with a Cluster of 25 Titans: 25 x 163.0 kH/s = 4075 kHash/s. Or with a cluster of 25 HD7970: 25 x 233.0 kH/s = 5825 kHash/s.
You also have to take into consideration that you don't have to find the exact passphrase for pasword cracking, you just have to find a combination of symbols that gives you the exact same hash. d7a8fbb307d7809469ca9abcb0082e4f8d5651e46d3cdb762d02d0bf37c9e592 is the SHA256 hash of "The quick brown fox jumps over the lazy dog". So "a!kL07gS1" might give you the same hash (it is just an example, it doesn't have the same hash) and you could decrypt the file with that as well. So what can you do for more security is either using a hashfunktion that generates a longer hash (07e547d9586f6a73f73fbac0435ed76951218fb7d0c8d788a309d785436bbb642e93a252a954f23 912547d1e8a3b5ed6e1bfd7097821233fa0538f3db854fee6 is the SHA512 hash of "The quick brown fox jumps over the lazy dog") or using an slow algorythm like blowfish. But with more hashing power the time needed to solve even those puzzles gets shorter. Just imagine what you could do with the 138 Thash/s SHA256 hashpower that the bitcoin network currently has LOL. Sure not much people here would have the money to build a cluster of 200 Titan, HD7970 or Xeon Phi just to crack some passwords, but it's no problem for the secret services (Do I hear Prism or GCHQ?
) or some criminal organisations to do this.
PBKDF2-HMAC-RipeMD160 boot-mode / AES: 451 kHash/s
OK, RipeMD took 40 seconds, SHA512 is 5 times slower, so it will take 10 minutes. Let's guess it was a simple password, it would take much longer with a better SHA512 password. But then remember it was just two HD6990. Let's see what we can do with a Cluster of 25 Titans: 25 x 163.0 kH/s = 4075 kHash/s. Or with a cluster of 25 HD7970: 25 x 233.0 kH/s = 5825 kHash/s.
You also have to take into consideration that you don't have to find the exact passphrase for pasword cracking, you just have to find a combination of symbols that gives you the exact same hash. d7a8fbb307d7809469ca9abcb0082e4f8d5651e46d3cdb762d02d0bf37c9e592 is the SHA256 hash of "The quick brown fox jumps over the lazy dog". So "a!kL07gS1" might give you the same hash (it is just an example, it doesn't have the same hash) and you could decrypt the file with that as well. So what can you do for more security is either using a hashfunktion that generates a longer hash (07e547d9586f6a73f73fbac0435ed76951218fb7d0c8d788a309d785436bbb642e93a252a954f23 912547d1e8a3b5ed6e1bfd7097821233fa0538f3db854fee6 is the SHA512 hash of "The quick brown fox jumps over the lazy dog") or using an slow algorythm like blowfish. But with more hashing power the time needed to solve even those puzzles gets shorter. Just imagine what you could do with the 138 Thash/s SHA256 hashpower that the bitcoin network currently has LOL. Sure not much people here would have the money to build a cluster of 200 Titan, HD7970 or Xeon Phi just to crack some passwords, but it's no problem for the secret services (Do I hear Prism or GCHQ?
) or some criminal organisations to do this.