轻量级校验和算法的不错选择？

I find myself needing to generate a checksum for a string of data, for consistency purposes. The broad idea is that the client can regenerate the checksum based on the payload it recieves and thus detect any corruption that took place in transit. I am vaguely aware that there are all kinds of mathematical principles behind this kind of thing, and that it's very easy for subtle errors to make the whole algorithm ineffective if you try to roll it yourself.I find myself needing to generate a checksum fo