But you know, you are not anonymous on Blockchain, you're only pseudonymous. If someone correlate your pseudonym with your real identity, they will know your entire financial history (on Blockchain).
There have been a few instances of specific payment patterns causing de-anonymization (which just means payments are correlated and identified as not-spoof, due to the way the Monero blockchain works). But to be honest if you think Monero in general can be broken you probably don’t know how it works well enough to make that statement.
One of the big concerns here is retroactivity: if you make decisions because you _think_ you’re anonymous but that changes for any reason in the future (compromised exchanges, insecure clients, sophisticated new analysis techniques, etc.) you can’t pull that history. That necessitates more caution than something where the stakes are lower if an attacker finds something clever to try.
I realize that things get leaked from centralized services, but there's a barrier to seeing that info. You put yourself at legal risk if you download one of those leaks and get caught. But there's no such risk with a public blockchain since the data was intended to be received by anyone who wants it.
Credit and Debit processors likewise directly log everything and sell it to marketing agencies to target you in detail.
If your reason to not use crypto-assets is that they are not private enough then you certainly should not use cash or credit cards either.
Even if it’s true that banks log serial numbers pervasively - most public sources say the opposite, except for things like money given to robbers - the many businesses which accept cash do not. Again, not perfect but the threat model is much easier for most people to reason about.
You would trust cash from your bank before Monero because some public sources you read promises banks never log serials?
I do not know what public sources you have read but FWIIW my interactions with financial fraud investigators in private sector and multiple government agencies have convinced me cash transactions and those that make them can be logged in great detail for people of interest if nothing else.
While complex I would recommend Monero or tumbled Bitcoin for people that require high privacy over anything else today. It also avoids the major risks of having to meet in person to transact as with cash.
That’s the key part: this is very different than all activity being routinely logged. Most of us never need to worry about this and someone in a hypothetical situation like you describe is presumably not a person of interest until afterwards, where that public blockchain history is a risk for the rest of their life.
Similarly:
> It also avoids the major risks of having to meet in person to transact as with cash.
This wouldn’t matter in your hypothetical scenario where physical goods need to be exchanged.
Again, my point is that this comes down to the marketing push. Even if the system works as planned, the number of people who made other opsec mistakes is high enough that in practice cash is not less safe.
I guess the assumption here is that retailers and the like would be compelled to provide that info to the government, but I'd still prefer that over the info going to absolutely anyone who wants it (since "the government" is a subset of "anyone").
I suppose I wouldn't know how much that data is worth unless I do have a crack for it, so I guess the point is moot :P
I can't blame people for losing interest / calling bullshit on crypto before spending hours diving into the details of L2, derivative wallets and multi-sig etc etc, details that ameliorate the skepticism. Also these things change over time, so maybe Lightning was unconvincing 3 years ago and skeptics just haven't given it a second look. (This is me, but I'm slowly being convinced that L2 really does make this stuff practical, but for a long time the transaction-per-second and unrecoverability of lost keys made the whole field very uninteresting)
It appears there are solutions available to a lot of concerns, but they require substantial knowledge of the ecosystem to use them and getting it wrong is permanent.
The account model: These networks have accounts and balances. You make a tx sending tokens from one account to another. It looks like normal banking more or less.
The UTxO model: These networks don't have accounts at all. Instead they have what are called "Unspent Transaction Outputs" or UTxO. Every transaction takes in a set of UTxO and outputs a set of UTxO. All the balances of assets in the inputs must sum up to the same values as the assets in the newly created UTxO and you can only ever spend a UTxO once. To spend a given UTxO some criteria must be met. The most often criteria is some signature that only validates with the public key of the private key being used to sign the Tx. This also can be generalised to other multi-signature schemes or even to supporting smart contracts (via policy ids and script refs/hashes).
Ethereum really was the network to push the account model into the forefront and now most networks choose to implement this over the UTxO model due to the ease with which you can get good UX and dev experience. Bitcoin, Bitcoin forks (SW or chain forks), Monero, Cardano, Ergo, Nervos, IOTA 2.0, and a few others use the UTxO model or some extension of it (ex: EUTxO or the Cell Model). One of the big upsides of the UTxO model is that all state is kept local instead of global however this local state also adds a number of complexities that make the model unintuitive to many.
------
So to answer your question: You'd create a Tx from your wallet. This Tx would consume some set of UTxO based on what you want to do and would then produce a number of UTxO going to any number of "accounts". In many UTxO networks, derivative keys are supported and you can give each person you want to receive money from a different derivative public key/address. If they were to send you money, it would go to your derivative address and it would be completely independent from all the rest of your UTxO until you do something on chain to tie them together (say by a delegation Tx in a PoS network, by merging UTxO, or by using UTxO from multiple derivative addresses in one Tx).
As for how you'd that the UTxO is valid: Essentially it just needs to exist on chain and not already been spent somewhere else. Monero for example uses this to their advantage with the "sum to 0" rule to provide a zero knowledge non-interactive proof that a given Tx must be valid without knowing the contents, sender, or recipients.