Could (merge) mining provide a vector for deanonymization?

Question

With the recent news that Digitalnote (XDN) is implementing merge mining in an effort to boost the hashrate by basically piggybacking off of Monero, I was wondering if this could lead to some leakage of information for Monero users who mergemine.

If a pool is monitoring payouts of both XDN and XMR to addresses that they can correlate to a miner's IP address, and they send the XDN tx with mixin of zero, does this leak any additional information compared to someone purely mining Monero? Is the only way to avoid this IP/address correlation by mining over tor or i2p?

Answer 1

When merge mining all you're doing is re-using your PoW calculation on different blockchains that share PoW algorithms.

Merge mining is therefore equivalent to, but more efficient than, running two or more miners in parallel against a mining pool supporting multiple currencies.

Since one blockchain doesn't know anything about the other (remember, you're only submitting PoW solutions) the XMR payouts cannot be tracked (by the properties of XMR) as they're moved around.

The XDN on the other hand, can be tracked, unless you take steps to hide your trail.

In conclusion, it's only slightly worse than if you were to only mine XDN, because the pool operator would also know your XMR address.

If you've re-used that XMR address, e.g. in your forum signature to solicit donations, they could watch the XDN blockchain and know what that forum user is up to.