- Transaction outs with guaranteed anonymity. An additional attribute for out is added: it can ONLY be used in the transaction with mixin level in ring signature not less than a given number. The feature is added to ensure the user's anonymity of transactions ring signature over time.
I might be missing something, but wouldn't it be more effective to enforce the mixin level on a more global level? Mixing in a key which appears somewhere else in an unmixed fashion will be less effective against smart blockchain analysis, after all.
For my point it is better to leave possibilty to have two subset of transactions outs - outs with guaranteed anonymity and regular outs, and different outs types could transform to each other during the circulation.
Actually unlinkability is e feature that not need to everyone, enforcing this feature for every transaction will blow up blockchain with ringsignatures.
So i've made this feature optional, but i believe still secure.