Wierd files in Etch Isos

[David Roberts <david@abexia.com>]

I've been assembling the etch isos from the jidgos in 
ftp://ftp.fsn.hu/pub/CDROM-Images/debian-unofficial/etch/jigdo/, and 
I've noticed that there are some very strange file names in many isos 
that can only be downloaded from ftp://ftp.fsn.hu/pub/debian-superseded, 
for example a 104,434 byte file named "rvR4p_R0Rdzusk7-y1MYBQ" or a 
59,263 byte file named "3-Und2B4-ZObujNzw1BpLA." Random file names like 
this are kind of scary. What are these files? Are they just some kind of 
filler? Should I be worried about them?

Thanks for your help.

David Roberts