Assume Alice is mining in the pool.
We can use an idea similar to the “fee emission box for mixing” to create a token-based mining pool solution by extending the above idea. This allows Alice to join the pool without having any Ergs to start with.
Someone, (say Bob) is willing to loan the Ergs to Alice in exchange for collateral in Bitcoin
Bob will create an “emission box” containing several Ergs. The box will contain a script allowing the Ergs to be exchanged with some token designated by Bob at the rate of 1 Ergs per token.
Bob will sell these tokens separately, which Alice will buy using Bitcoin.
She will store these tokens in a box protected by the script “minerPubKey == alice” to protect against the broadcast attack discussed above.
When mining, Alice will spend this token box along with Bob’s emission box, exchanging the tokens
for the Ergs to go in the pool transaction.
Since we would like Alice to be able to get back her Bitcoins at a later date, as long as she pays back Bob the loan, we can make a provision for the tokens to be purchased back by Alice after the reward becomes spendable. She can then exchange the tokens back for Bitcoins.