MD5 is a checksum algorithm, it provides a fixed length output for any input, and is not deemed reversible (In practice, you can however reverse MD5 because of collisions).
Saul Rennison wrote: > Wait. Is a hash a form of encryption (such as MD5) / encoding (Rot13), > which is potentially reversible, whereas checksums are purely a way of > providing a shorter output semi-unique to the input. > > Amirite? > > Sent from my iPhone > > On 8 Jul 2009, at 02:52, Bob Somers <[email protected]> wrote: > > >> SHA-1 is not a checksum, it's a hash. A checksum (like a CRC32, CRC16, >> etc.) is different from a hash. >> >> Also, what Jonas and Harry mentioned applies. Even if it is a hash and >> not a checksum, it could easily just be replace unless it is signed. >> >> --Bob >> >> >> >> On Tue, Jul 7, 2009 at 2:01 PM, Dave Gomboc<[email protected]> >> wrote: >> >>>> Checksums really don't provide security against tampering, as they >>>> are >>>> too easy to manufacture. They're more often used to detect casual >>>> corruption errors like those that could be introduced during network >>>> transmission. >>>> >>>> --Bob >>>> >>>> >>> I'm not sure what your definition of "easy to manufacture" is, but >>> I'm not >>> aware that the frequently-used SHA-1 would qualify as such. >>> Finding a >>> collision has been proven to be possible faster than via brute >>> force attack, >>> but I would think that doing so with contrived data that must also >>> serve as >>> a working substitute for the original data would still be pretty >>> difficult >>> (as of July 2009, anyway). Also, there's better checksums than >>> SHA-1 that >>> could be used in its stead. >>> >>> Dave >>> _______________________________________________ >>> To unsubscribe, edit your list preferences, or view the list >>> archives, please visit: >>> http://list.valvesoftware.com/mailman/listinfo/hlcoders >>> >>> >>> >> _______________________________________________ >> To unsubscribe, edit your list preferences, or view the list >> archives, please visit: >> http://list.valvesoftware.com/mailman/listinfo/hlcoders >> >> > > _______________________________________________ > To unsubscribe, edit your list preferences, or view the list archives, please > visit: > http://list.valvesoftware.com/mailman/listinfo/hlcoders > > > _______________________________________________ To unsubscribe, edit your list preferences, or view the list archives, please visit: http://list.valvesoftware.com/mailman/listinfo/hlcoders
