opcoin trickery

A new tool (opcoin) has been added to opmsg's contrib directory,
which allows to convert bitcoin keys to opmsg personas.
You may find convertable public BTC keys in any
BTC (P2PKH) transaction. So you just go to your favorite
blockchain website and search for an address that you know
belongs to a certain person and import their pubkey(s).
The calculated BTC address (match) ensures that its really
the key you want to import and will since then appear
as the personas name inside opmsg keystore.

Voila! Suddenly opmsg became the crypto system with the largest
keybase world wide! One more benefit: you can ensure that a
dedicated persona name is in possession of a private key,
by authenticating them via micro transactions.

Read more details here.