Possible descrypt performance issue

[me.scotty]

Please verify again and if you can reproduce it post an issue on GitHub and include all information devs need to reproduce it locally so we can fix it

Many thanks for your response.

My gut feeling is still leaning toward this being an "inherent in the design" issue.

I don't know how JtR (which also utilizes bitslicing) behaves in cases like this, because I stopped using it when hashcat came along...


But since you seem to think it can be "fixed", I'll post the issue on github.


Note: It's more important than it first appears, because while descrypt officially can have 4096 salts (I've seen some spec extensions here and there), in practice ~60% of the hashes contain only 100 salts (the digits).
(Apparently, the scripts that generate the hashes from passwords supply a random salt that's not entirely random.)

Code:

(Note: single hash masked)

Session.Name...: all
Status.........: Running
Input.Mode.....: Mask (?1?1?1?1?1?1?1?1) [8]
Hash.Target....: xxxxxxxxxxxxx    
Hash.Type......: descrypt, DES(Unix), Traditional DES
Time.Started...: Tue Jan 12 15:37:35 2016 (6 secs)
Time.Estimated.: Fri Jan 29 11:19:59 2016 (16 days, 19 hours)
Speed.GPU.#1...: 76175.5 kH/s
Speed.GPU.#2...: 76185.9 kH/s
Speed.GPU.#*...:   152.4 MH/s
Recovered......: 0/1 (0.00%) Digests, 0/1 (0.00%) Salts
Progress.......: 1019215872/218340105584896 (0.00%)
Rejected.......: 0/1019215872 (0.00%)
Restore.Point..: 0/916132832 (0.00%)
HWMon.GPU.#1...: 98% Util, 51c Temp, 90% Fan
HWMon.GPU.#2...: 98% Util, 50c Temp, 30% Fan

Session.Name...: all
Status.........: Running
Input.Mode.....: Mask (?1?1?1?1?1?1?1?1) [8]
Hash.Target....: File (C:\descrypt(x13).txt)
Hash.Type......: descrypt, DES(Unix), Traditional DES
Time.Started...: Tue Jan 12 15:35:29 2016 (8 secs)
Time.Estimated.: Wed Apr 06 15:14:53 2016 (84 days, 22 hours)
Speed.GPU.#1...: 15133.2 kH/s
Speed.GPU.#2...: 15144.5 kH/s
Speed.GPU.#*...: 30277.7 kH/s
Recovered......: 0/13 (0.00%) Digests, 0/1 (0.00%) Salts
Progress.......: 251658240/218340105584896 (0.00%)
Rejected.......: 0/251658240 (0.00%)
Restore.Point..: 0/916132832 (0.00%)
HWMon.GPU.#1...: 99% Util, 57c Temp, 82% Fan
HWMon.GPU.#2...: 99% Util, 56c Temp, 30% Fan