Why don’t you use OpenPGP, GnuPG or similar for verification?
In an ideal world, this kind of encryption and authentication would be widespread, well understood and easy to use. But it’s not. For the vast majority of our readers, it would be a barrier and a distraction. The techie-minded users who would understand it and benefit from it are savvy enough to get authenticated alerts from other sources such as RSS feeds. We will continue to review this question but our ultimate goal is to encourage users to transition to the RSS feed rather than rely on email. As an aside, similar services around the world work in the same way. For example, De Waarschuwingsdienst in Holland or US-CERT in the USA.
