On Mon, 19 May 2008 09:32:08 -0400 Patrick Roehl <[EMAIL PROTECTED]>
wrote:
:>Is it possible to determine if a record buffer has changed without storing
:>the whole buffer? A checksum doesn't seem to be enough, since rearranging
:>two fields in the buffer would yield the same checksum result. That is, if
:>the LAST-NAME and FIRST-NAME fields get switched, the buffer has changed but
:>a checksum might not pick that up.
:>I'm hoping someone has thought this through before. Is there an available
:>algorithm that can calculate a hash that would detect any buffer change, or
:>an extremely high percentage of them? (I'm aware of the CBTtape offerings
:>but don't know if they would work well for this.)
:>Proposed Usage: Get buffer, calculate hash, save hash. Get buffer some
:>time later, calculate hash, determine if buffer changed.
SHA-1 should be more than adequate.
Also, a checksum with multiplying each word by rotating {1,2,3,5,7,11} might
help with getting rid of aliases.
--
Binyamin Dissen <[EMAIL PROTECTED]>
http://www.dissensoftware.com
Director, Dissen Software, Bar & Grill - Israel
Should you use the mailblocks package and expect a response from me,
you should preauthorize the dissensoftware.com domain.
I very rarely bother responding to challenge/response systems,
especially those from irresponsible companies.
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO
Search the archives at http://bama.ua.edu/archives/ibm-main.html
