June 17th, 2013, 08:52 AM
How to prove DES semiweak key
Hey, my task is to prove that K=E0E0E0E0F1F1F1F1 and K=1F011F010E010E01 is semiweak key for DES (IT study).
I have found out this wiki page http://en.wikipedia.org/wiki/Weak_key
And there i have found this pattern
So i used online des encryption generator to check out this pattern
this one is saying it need only 8bit keys: http://des.online-domain-tools.com/
this one returns evry cripth different result http://www.tools4noobs.com/online_tools/encrypt/ (broken or what ?)
well it didnt't success. i was trying out with pairs of keys given at wiki site like
0x011F011F010E010E and 0x1F011F010E010E01
0x01E001E001F101F1 and 0xE001E001F101F101
0x01FE01FE01FE01FE and 0xFE01FE01FE01FE01
0x1FE01FE00EF10EF1 and 0xE01FE01FF10EF10E
0x1FFE1FFE0EFE0EFE and 0xFE1FFE1FFE0EFE0E
0xE0FEE0FEF1FEF1FE and 0xFEE0FEE0FEF1FEF1
but didnt get good result. How should I prove they are semiweak keys ? Hope you will guys help me, thank you!