Can I check packages integrity with debsums on sums chech failed DVDs?

[Sthu Deus <sthu.deus@gmail.com>]

Good day.

I have installed Lenny from a DVD-1 that has passed sha1sum check. Then I added
some software from the DVD-2 and -3 - that did not pass the check successfully.

Is it correct to suppose that the OS installation is not secure because od the
failure on sum check of those 2 DVDs and therefore debsums check of each
package will result in false info?

CAn the reason be that the images were downloaded using:

1. windows-machine

2. the windows commander and a browser

? 

Also, I tried:

/var/lib/dpkg/info$ dpkg -S ace-of-penguins.md5sums | grep var

and got:

dpkg: *ace-of-penguins.md5sums* not found.

How I can find out from whence the file has come?


Thank You for Your time.