Ring signatures are unwound when the tax authorities require you to provide your password to justify your tax basis.
Use more than 1 wallet? Plausible deniability is such a nice toy. And why password? Give them a viewkey to whatever wallet you want to have exposed. Ideally you can even password protect a wallet with different keys who then unlock whichever viewkey you want to release, like the hiddenos feature of safeguard and truecrypt.
I am not understanding how you think this helps?
If the tax authorities demand my private keys so they can trace on the block chain from a particular tx that I claim to be my tax basis to the transaction where I am claiming a capital gain, then how does your suggestion alleviate that demand?
Since Monero has private keys, I can't refuse their demand if it is the law.
http://www.nestmann.com/could-the-government-force-you-to-tell-your-deepest-darkest-secrets...
Neverthless, since it would be difficult to tie a person to an XMR address and then impossible to tie an XMR address to a particular transaction without the txid, it's reasonable to think that it wouldn't be too hard to have two accounts - one that could be provided in the case that a court does force the issue.
At that point, how would they be able to prove that this is the "wrong XMR account"?
If the tax authority wants to trace on the block chain from the transaction that I am claiming is my acquisition point (tax basis) to the transaction I am claiming is my disposal point (capital gain), then as far as I can see possessing a second address or wallet that doesn't trace from the former to the latter on the block chain doesn't help me in any way. Also the I2P layer is irrelevant since I am choosing to tell the tax authorities which txs on the block chains are mine because it may be a reporting requirement.
Now once I have reported those transactions and by law also reported (e.g. in the USA IRS Form 1099) the identities of who I have received the coins from and sold them to, then I've revealed my anonymity, the anonymity of the entities I transacted with, and reduced the anonymity set on the block chain for all those who mixed their ring signatures with mine.
I wrote upthread that anonymity could be unwound for ring signatures if authorities can require you to reveal your private keys (a.k.a. passwords), i.e. allow you to have privacy to the public but not to the government. Astute readers surely smugly ignored me thinking that if the authorities already know your identity in order to require your passwords, then you don't have anonymity. Well this unstated rebuttal falls apart on several levels. One as I said, you revealing your password lowers the anonymity set for those who didn't reveal. Secondly, you may wish to report for tax purposes some funds you bring from the non-reported anonymous world back into the mainstream fiat world, so then the authorities may require you reveal your passwords so they can verify the tax basis you claim for your capital gains. As you know the rulings for example in the USA is that mining is income and the tax basis for capital gains starts at the time of the coinbase transaction.
You may think this is unlikely but I can vouch for example there is a bank secrecy law in the Philippines which the TPTB have not been able to repeal, so the SOBs have apparently paid (or somehow fooled) the risk management departments into sending SMS every time there is a transaction on your account (if you are an American at least), thus the authorities know everything that is going on in your bank account. Bank secrecy thus nullified.
