Bitcoin is pseudonymous. Every member can be uniquely identified but if you are careful not to link your pseudonym (e.g. wallet address) to any personally identifiable information, nobody else can. But this is really hard when it is about money since in general you'd want to spend that money an that's where the link appears. As long as you don't spend the money, there is no information to link.

There are ways around this problem. See: https://local bitcoins.com

Doesn't completely de-anonymize you but it does reduce the set of people who have uniquely identifiable information to 1

That site requires identification. So the owner of the coins is known by everyone with the dataset (which that will be shared with chain analysis companies), as well as the website owners and the trader you trade with. Pretty big set

Monero

We're having a discussion on HN about a specific person moving a specific amount of money around. That by itself is basically the opposite of privacy.

Ansil849 already said this, but when talking about things like this there are actually multiple related, sometimes orthogonal, factors:

Anonymity - the quality of the user being unknown

Privacy - the quality of the user's actions being unobserved

Authenticity- the quality of the user's actions being certainly the user's

Bitcoin provides pseudonymous transactions, which may approach anonymity if the user is careful. It does not provide true privacy as all transactions are public. But the purpose of the transactions is not communicated, though may be inferred if the parties are identified. If I transfer $20 in BTC to a pizza joint, you can guess that I bought a pizza, but it's just a (well-founded) guess. It provides a high degree of authenticity in that it is a hard problem (in the mathematical sense, unless your keys have been obtained by an adversary) to fake a transaction.

Yes, I have a PhD in cryptography and designed two of the first privacy-preserving extensions to Bitcoin. Bitcoin provides pseudonymity. If no other information can be inferred about a transaction from other sources, users may be able to protect their privacy. In practice this is extremely challenging, and the information leakage this post is discussing is highly unnecessary, and a weakness of Bitcoin.

Anonymity ≠ privacy

We're having a discussion about an unknown account - which may or may not be an individual person - moving specific amounts of money around anonymously, not privately.

You're describing pseudonymity, not anonymity. We know that a specific user has moved money under a pseudonym. If they do other things with that money, we'll learn more. These are very different concepts.

https://en.wikipedia.org/wiki/Pseudonymity

We don't know the person though; we know a wallet address. Similar to a bank account number; it's just a number.

I get what you mean, the transaction is public, but that's the point of bitcoin / cryptocurrencies.

Publishing the value and timing of specific transactions isn't actually the point of Bitcoin and specific cryptocurrencies, nor is it necessary to preserve the total amount of the currency. Satoshi specifically called the privacy issues in Bitcoin out as a weakness to be improved upon, and several projects inside and outside of Bitcoin have been doing this.

I can also be anonymous if I never speak or leave my house, but that's not really how it works, is it?

In this case, it seems to be exactly how it works. Someone is opting to 'never speak or leave the house', and can afford to do so.

Maybe it applies to very specific "Bitcoin as store-of-value" use cases, but it definitely doesn't apply to any use case you'd actually want for electronic cash.

Also, even the fact that we're discussing the existence of this transaction implies that Bitcoin is not anonymous.

Exactly. A messaging app isnt private just because you never message anyone

No, you can't.

Your house has to be registered to someone and you have to declare who lives in it, if it's yours.

Anonymity is not about being a private person.

> Your house has to be registered to someone and you have to declare who lives in it, if it's yours.

I don't think this is true in every jurisdiction. You can certainly have a property registered under a corporate entity, and there are jurisdictions in the US that allow for anonymous corporate ownership. Further, I'm not aware of any requirement where you must declare who is residing in a property. I've had family members from abroad reside in my house for over a year without informing any authorities, for example.

The fact that you didn't doesn't prove you shouldn't

I'm not from US. I don't know the technicalities, in Italy for example you should declare who's residing in your house, even if it's a no paying guest

Many don't, but it's still a requirement

BTW the point was anonymity is not about being anti social, it's about hiding your true identity

If you stay home and never talk to anybody you're being secretive, but probably are not anonymous (police can still come and knock at your door because neighbors called then since you came in and never went out, for example)

Professional gangsters don't register their house in their own name. They're happy with a girlfrield, or 'similar,' and just use their apartment and travel all over the world uninhinged. All cars and apartments etc are usually registered in someone else's name. Someone """"legit"""""", so to speak, apart from the affiliation.

If you have tons of illegal money it's not the worst thing to live in a ~~ 'moldy' apartment and eat SCSI every day and know that you _really_ have a __ton__ ___of___ ____money____

Learn to be a criminal, theoretically of course

You said it

They are gangsters

Bitcoins main feature isn't being anonymous and also the wallet is more likely an exchange wallet than some random billionaire's. There's privacy coins that heavily lean towards achieving anonymity. But I mean if I had a billion dollars and I wanted to have it in Bitcoin, there's nothing stopping me from having one hundred million Bitcoin wallets each with $10. If performed properly, I think that would sufficiently obfuscate my identity until I had to liquidate them.

That's the whole idea behind the blockchain. Everything is recorded in ledgers

Most of the genuine use-cases would do much better with privacy, it goes hand-in-hand with payments that traditional finance may try to censor.

There is privacy-focused crypto like Monero though.