cracking a licence file

[nitsua22]

hi there, first post on this forum :-)

i was wondering if anyone knew the following type of protection.
the software i'm using checks a licence file.

the software itself could be downloaded from a site, for the serial i had to send my mac-adress and they send me a licence back.

the licence works for only a few days (well, if i should believe the file name which contains a date a few days from now).

in a normal text editor the file looks like this:

0x00 0x86 0xb8 0x58 0x3d ... enz

in Hiew (decode style) can be found a lot more. but i cant find anything checking my mac-adress or sending the time of the trail.

i know this is about software and not about games, but does anyone know these types of protection or give me some more information about it?

ps. hours and hours of googling have past ...

kind regard..