If you can tie the shield into KBFS, that's even better. It's not enough to protect a company from attacks, though. People may still click that random document coming in via e-mail that claims to be from a co-worker. A mandatory technical solution on that end, no matter what the actual technology looks like under the hood, would be essential for protecting people from making these kinds of mistakes.

The value proposition of automatic and transparent public key cryptography is strong, and what I love about Keybase. Just thinking of other ways that can be applied transparently.