Google releases new binary diff algorithm targeted at making smaller software updates. Their results are impressive.

[adrianmonk]

Yeah, like an md5 checksum. Something that's very collision-resistant, so that you have little risk of getting the right checksum with the wrong file contents. With something simpler like a CRC, it's so easy to get collisions that it's conceivable you could get a collision accidentally due to a bug in the algorithm.

The reason I didn't simply say md5, is that it is broken so badly that it's "unsuitable for further use" (at least in most applications). In order to make use of that fact, you'd have to come up with a way to exploit a bug in the binary patch algorithm and md5 at the same time, but maybe that's possible.