The Chicken and Egg Problem for checksums was solved for the IP header checksum, and the TCP payload checksum back during the 1970s. When calculating the checksum, set the checksum field itself to zero. When verifying the checksum, skip over the value that is actually present. Perform the calculation as if it was actually set to zero. CD and DVD images could do the same thing. It would be enough to append a single 32-bit CRC just to ensure that your download wasn't corrupted, or that you had a good burn, but if you wanted to make sure that the Russian Mafia hadn't patched your kernel, you could add one entire 2048-byte sector to your image, and fill it all up with one big cryptographic hash. Don Quixote -- Don Quixote de la Mancha quixote@xxxxxxxxxxxxxxxx http://www.dulcineatech.com Dulcinea Technologies Corporation: Software of Elegance and Beauty. -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
