[brl]

Maintenance of public keys is automated, by which I mean the user does not need to do anything manually for them to be published and recertified before they expire.

Private keys don't need maintenance after generation since they are simply stored on the user's computer.

[diafygi]

So you can't read your email on another computer or phone?

[brl]

You can copy your private keys to another device obviously, and eventually Nyms can help you do this by brokering an end-to-end encrypted tunnel between devices to transfer keys securely.