As you've undoubtedly heard, SHA-1 has been “broken” - and now Bruce Schneier explains what that really means (along with some good background for those unfamiliar with cryptography in general).

Basically, this is an interesting (albeit not entirely unexpected) development in cryptography, but has little immediate impact on the average user. In Bruce's words:

For the average Internet user, this news is not a cause for panic. No one is going to be breaking digital signatures or reading encrypted messages anytime soon. The electronic world is no less secure after these announcements than it was before.