creighto, I am only talking about verifying the absence of double spending. Of course, you can always receive a coin and just hope. That is clear.

I don't think that physical coins have this issue. Or gold. Firstly counterfeiting is really difficult, secondly "bill verifiers or gold verifiers" are local machines. If someone could
counterfeit gold or coins in a way that no local machine could detect, then it would be the same. But no one can do that.

With bitcoin in the version I have seen (not red's), you cannot build a local machine that verifies it. I don't understand what red exactly is proposing.


NewLibertyStandard, your suggestion is a bank, that the payer and the payee need an account with. I don't mind, but I don't think it is an answer to the issue of this thread.

What I see as the ideal solution has these properties.

1. You can participate by just having some software on your computer/phone.
2. The coins are stored by yourself. A coin is a string of characters, no physical gold or so is involved. Encryption keys are fine if you can generate them yourself.
3. No accounts or registrations with banks or governments are needed.
4. Payments can be totally verified including double spending checks. Tiny probabilites can be ignored. But I mean tiny, not just reasonably small.
5. If a person is traveling to a city, he (she) can prepare for the visit by exchanging coins. This exchange can be slow. After arriving to the city, the person can make fast payments
to a person residing in that city. By fast payments, I mean payments that are completely validated in a time frame that does not depend on the total size of the coin system. In other words local trade should be possible, even if the digital cash system is used all over the world (or galaxy). The preparation before arrival is important here. Of course, many coins can not be verified, fast, against double spending by the payee, but there should exist some coins that can, given the location. And the payer can prepare before arrival by getting such coins.
6. No issuer on whose honesty the system relies.   


1-5 is possible with an issuer. The coins have a tag that denotes where double spending will be verified. The issuer keeps the information about those coins on their servers in that location. In other words, the issuer's distributed hash table follows some rules for what coins are stored where. And those rules are publicly available.

1,2,3,4,6 seems to be bitcoin if I understand correctly.

Does 1-6 exist. Is that what red is saying?