Improving availability and guaranteeing integrity in ISO - internal sha1sums

[David Timms]

Jesse Keating wrote:
> On Friday 08 June 2007 22:20:14 David Timms wrote:
>> The simplest way to do this would be for the iso spin system to perform
>> an sha1sum * > SHA1SUM within each directory of an iso spin, and have
>> each result inserted into the corresponding directory.
> 
> What is it we do when we implantisomd5 which is used by media check?  Can't 
> you make use of that?
I am not sure how you do that - how can you include inside a piece of 
data a checksum that uses the data {including itself} to calculate the 
checksum ? {sounds like one for the crytologists}. Perhaps it is outside 
the data area, but then you have no way to know if the implanted 
checksum is broken or that data itself {although I imagine it is likely 
to be the data}.

What I am after is a checksum for each file present within the iso, not 
the result for the whole iso. Is there such a thing already present ?

DaveT.