You didn't read very well as my example was 3 confirmations being *undone* (there is no real limit of rewinding beyond the difficulty to do this and the last "checkpoint").

So such attacks are very much *of concern* but I'm just pointing out that this concern is not about *invalid txs* or *invalid blocks*.

Let's say that we have the following blocks:

A1 -> B1 -> C1 -> D1

but then someone with >50% of the hashing power creates this:

A2 -> B2 -> C2 -> D2

and the rest of the network agrees that the second set of blocks is both *valid* and *superior* (in terms of POW) than the first set.

So now A1..D1 are *discarded* and replaced with A2..D2 (what came before A1 and A2 is identical and therefore not of concern in terms of any change).

What this could mean is that txs that were valid (with 3 confirmations) in A1..D1 are now no longer valid after the re-org.

This is why you are recommended to wait for confirmations (the more value you are risking the more confirmations you should wait).

Again - *no* you can't create invalid txs or invalid blocks (what have you guys been reading to give you this idea?).

The issue is with potential re-orgs and not with validation.

The rules that apply to the blockchain is in accordance with the software that you are running and not to do with the POW determination of the longest chain (that applies *after* validation).

Again - you can't create invalid blocks and they somehow become legit due to >50% of hashing power (that's not how Bitcoin works).

The rules about what is valid/standard is built into the software itself (so you need to change your software to change those rules).

(unfortunately ad-sig posters don't care about facts as they just want to post and get paid - so you constantly get nonsense posts being made on this forum)

Regardless of whether or not the account buyer was tricked if the OP can actually prove that it is her account then the buyer should lose (they got tricked by the seller and that is not the fault of the original account owner).

If you are going to buy accounts on this forum then you should realise that it is very likely that you will be buying hacked accounts (as this forum doesn't care about trying to prevent this from occurring same as it doesn't try and prevent ponzis and altcoin scams which abound).

So if you decide to buy accounts on this forum and you get burned then I have zero sympathy for you (because you could have simply created a new account and waited for it to mature but decided you didn't want to bother with the only reason being "greed").

There is simply no "legit" reason to buy an account - create a new one and "do your time" (like I and most other more seasoned account holders did).

When I joined you had to go through "newbie jail" which they got rid of so I can't see any reason at all to be buying accounts. Would the buyer of the account in question care to justify why they should retain said account if it is proven to have been hacked?

This is most likely not what you are wanting as a reply but using my code here: https://github.com/ciyam/ciyam/blob/master/src/crypto_keys.cpp#L808 you can see there is a "p_message" argument that is used to add an OP_RETURN output (with a zero amount) to a raw tx.

The code that actually adds the OP_RETURN to the tx is here: https://github.com/ciyam/ciyam/blob/master/src/crypto_keys.cpp#L945 and you'd need to change the "c_zero_amount" (so it would require coding changes to "burn" BTC as I didn't design my code to do that).

I have no idea whether the Bitcoin RPC makes this any easier to do so perhaps Danny can chime in if he has a simpler method (my guess is that no-one has probably made such a thing as it is not something that 99.999% of Bitcoin users would want to do).

An OP_RETURN is simply another output for a Bitcoin TX (you can only have one per tx for a Standard tx).

Typically such an output has a zero value (as it is normally used to append some "data" to a tx) but there is no reason you can't give it a value (which would permanently "burn" that value).

Not sure if the raw tx commands enable you to do this easily or not though (but if the OP really wants to be able to do this then you could fairly simply modify my own raw tx stuff to do this).

Illegitimate blocks doesn't make sense (i.e. just because someone has the hashing majority doesn't mean that they can change consensus rules for others and in particular I am talking about a potential hard-fork).

The main concern would just be transactions being confirmed and then later becoming unconfirmed and replaced by others transactions through a re-org (i.e. done on purpose in order to "double spend").

It should also be pointed out that hashers could simply switch pools (as has occurred before) if they were concerned that the pool that they are using is getting "too powerful".

Yup - and what is important to point out is that Gavin doesn't say exactly how he verified the signature (i.e. did he type in the same message?).

And even if he did - surely we are not just supposed to "take his word for it" (as that is not how Bitcoin works is it).

Gavin did respond and was apparently "surprised" at what had appeared in the guys blog (which supposedly was not the same as the demonstration he was given).

The fact that Gavin "wasn't allowed to keep the signature" from the personal demonstration is rather suspicious though in itself (and Gavin has admitted that it is possible that he was bamboozled).

Perhaps the key question was whether Gavin verified the double hash of the phrase that he had provided to CW (he has not commented about that AFAIA) because if he didn't then he could have been tricked in exactly the same manner (i.e. the hash not actually being correct).

And yes - if you can't keep to the topic (which you keep on showing that you can't) then please stop posting your vitriolic nonsense as I don't think anyone else here is really that interested in your insatiable need to try and insult people (be it myself, @gmaxwell or whoever).

We all know that according to you "no-one understands anything as well as you".

So guess what - no-one is going to bother and try.

(you should consider just starting your own forum where you do all of the posting yourself)

Priceless quote from the guy with the supposed huge IQ (sounding like a 4yo).

Now getting back to the topic - if CW has broken SHA256 it seems rather incredible that the collision he found just so happens to match some Sartre document (because he personally likes Sartre) and one of (or the) first Bitcoin transaction(s).

He also somehow generated an identical signature to one already in the blockchain (which would not happen even you are signing the same double hash value).

So we have either that scenario - or the scenario where he just copied and pasted the first (or one of the first) Bitcoin txs signature and then pretended the rest (i.e. a hoax as this topic is about).

Statistics would be very strongly on my side here.

I don't take orders from the likes of you (i.e. a dick) - and we are still waiting to see your amazing cryptographic hash algorithm.



Please do show us your algorithm so that we can make sure that @gmaxwell can review it!

Priceless - please show us your own cryptographic hash algorithm - we are all dying to see it!



My guess is that you are going to offer your amazing cryptographic hash algo (which I am guessing has been peer reviewed by many experts all over the world) to Bitcoin?

No wonder @gmaxwell isn't very interested in what you have to post!

(and unlike you I am not claiming to have designed a cryptographic hash algorithm)

Please name me one single SHA256 collision - idiot!

And now work out for me the odds of CW having found such a collision (and it happening to come from whatever Sartre document).

It is your ego that prevents you realising why @gmaxwell (assuming it was him) trashed your silly topic.

Your ideas about facts are far removed from the rest of the world and are again off-topic (so I am not going to waste my time bothering to refute such off-topic snide remarks from you).

Why not try and just stick to the topic rather your insatiable need to attack other forum members?

(it doesn't add anything to your points at all)

Back on topic - CW is apparently not only go to show the world that he has broken SHA256 but also how he managed to create an identical signature to one already existing (because even the SHA256 collision would not result in an identical signature as anyone who knows how this stuff works will attest to).

The only idiot here is you - and I'm glad you keep on posting your belief in this CW guy as it is just going to make you look even more idiotic as it pans out that he is the fraud that he is.

And your ad-hom attacks upon me are really not on-topic are they?

(so why don't you just stop the butthurt remarks aimed at me and stick to the topic which is CW and whether or not he is a fraud)

And you really believe that the double hash of some Sartre document just happens to be identical to the hash of the first (or one of the first) txs in the blockchain?

Am guessing you have a very strong belief in the tooth fairy as well.

Again - if he wanted to demonstrate that the double hashes match that would be trivial to show (but of course again he won't do that now will he).

It should be noted that not a single SHA256 collision has been found to date (so CW's claims of world's firsts and amazing achievements just keep on piling up).

He never used the hash of any Sartre quote (that was just misdirection) - the double hash that he used was simply that used in Satoshi's tx along with the signature that was used in the tx.

(basically he just copied and pasted from the blockchain then put together an elaborate pretense that he had somehow managed to sign something else using a private key known to belong to Satoshi)

Even the silly BBC report has been corrected once they finally worked out that they had been tricked.

You are simply unable to even do the most basic research and instead just resort to calling me names.

No wonder you can't write any code and no wonder due to your attitude not one person on this forums wants to write any code for you.