should be able to cat public keys.

Public keys should be accessible as ipfs objects:

```
> ipfs id -f=""
QmTcSiJtSRiaGLtfV2qPdhUJFxqYGCNpZfzYhYWWXB4p8p
> ipfs cat QmTcSiJtSRiaGLtfV2qPdhUJFxqYGCNpZfzYhYWWXB4p8p
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
```

this means we'd have an object wrapping a public key, which is fine and may be used to link to other useful information, but it does mean a bit of working in the pk exchange to ship the ipfs format.