Goodbye, world!

[jamyr]

But then, I cant help but wonder what really made Lauda leave the community, at least, he or she would have maybe taken some time off, and come back whenever things are fine, But leaving everything he or she have struggled to build and achieve through out this years to say goodbye is kind of abnormal to me, I don't know what you guys think, maybe I need a mental reorientation but honestly, I don't get it.

Lauda ran out of lives.

Thank you everyone in advance, quite the 9 lives that some Kitty had here.

Seriously though, all we can do is speculate to why Lauda left forever.
From the OP, unseen pressure was the reason. With his/her popularity in the forum, no wonder pressure got to her/him.

or perhaps he/she's done enough for the forum and have to focus on rl stuff.

This is funny btw:

https://bitcointalk.org/index.php?topic=5096181.msg49185800#msg49185800

[1714469846]

1714469846

[1714469846]

1714469846

[1714469846]

1714469846

[1714469846]

1714469846

[nullius]

This is my first time of coming across this topic and sincerely, I was so touched that i went sober, indeed , this is one of the goodbye message ive read that really touched my heart, and i am also glad to see that this user have indeed, touched lives on this forum before saying goodbye.

This nonexistent cat appreciates your kind words.

Free images of Lauda!

Seriously though, all we can do is speculate to why Lauda left forever.
From the OP, unseen pressure was the reason. With his/her popularity in the forum, no wonder pressure got to her/him.

Indeed, we can only speculate.  I decline to say my own theories, for I have no wish to sow rumours.  In private, she refused to tell me why.

or perhaps he/she's done enough for the forum and have to focus on rl stuff.

It is a mundane theory, boring, unlikely to excite the imagination—and maybe wise and insightful.  I hope it is the case.  In the past, she said some things to me which would seem consistent with that (and she repeatedly urged me to leave the forum myself), but her final post seemed to imply otherwise.  Who knows.

Lauda left a negative feedback(deserved) to me,but she was kind enough to update it before he/she/it went bye bye.

To where ever Lauda is, Thank you and stay grumpy!

That is fair of you.  Many people who got the red cat-scratch only bear a grudge about it, regardless of how much it was deserved.  I see that she neutralized yours in May 2020, about five months before she left.

have there been any confirmation if Lauda was a she or he or it?
Maybe she confirmed it here:

https://bitcointalk.org/index.php?topic=5098579.msg49276971#msg49276971

Now, that is an interesting subject of speculation!  There has been endless talk about it; sometimes, there have even been whole threads devoted to that question.  It is probably the most productive use that the Reputation board has ever had.

She (he? whatever) caused this confusion for privacy, not for jollies.  She once pointed out to me that male/female is a significant bit of personally identifying information.  He was a privacy fanatic.  Concealing that one bit of information theoretically doubled her anonymity set—although the effect in practice would be disproportionate, given the disproportionate distribution between men and women in these types of venues.  Partitioning and intersection attacks to attempt deanonymizing the cat cannot exclude known males, and cannot exclude known females.

It is not unprecedented to incite such confusion for unusual reasons.  For instance, I know of a psychiatrist-blogger who subtly switched back and forth between apparently-male and apparently-female, without ever explicitly claiming either.  He did this to make his readers’ assumptions a part of whatever message he was presenting—and sometimes, to show them how wrong their assumptions can be.  As a professional psychiatrist, he pulled this off most excellently.  But he was not a privacy expert; in his case, he was eventually doxed as a man.

Earlier in this thread, I quoted a post in which Lauda presented a female image and spoke of her “husband”, in a context where I think that she was probably joking; see also my take on it.  Other forum members have dug up posts where Lauda seemed to indicate or imply being a man.  I think it’s likely that the apparent contradictions were not unintentional.

Some longtime forum regulars are almost sure that he was a man.  I think that she was probably a woman.  I pestered her endlessly about this question; all that she would tell me was, “I’m a cat.”  Flip a coin, pick a pronoun, and stick to it.  Whatever the correct guess may have been, she/he was never offended by wrong guesses.

[garlonicon]

someone doubled the prize money

Also, there is some traffic related to this address on testnet3.

I myself could reproduce the private key from scratch, using only the information that is publicly available on the blockchain.

I have made it so that the puzzle can be solved with any computer that could run Bitcoin Core.

I could be wrong, but if the whole challenge can be completed with Bitcoin Core, then I guess it is all about signing some message, because Bitcoin Core can sign any message with any key, there are commands for that. And then, it may require just grabbing R-value from the signature (that is deterministic), and using that as a public key, so the private key could be then reached by reproducing k-value for some trivial key with trivial message. But even then, there are a lot of options, definitely more than I could brute-force. So it is not yet taken, because it is based on "security through obscurity".

Another question is if that challenge will be upgraded to Taproot? Because if it is really based on HMAC-SHA256 or things like that, then it could be as well based on Taproot, where there are endless possibilities for a brainwallet TapScript, exactly in the same way, as there are endless possibilities, when it comes to signing some transaction. As I said, it is based on obscurity, and that's the only reason why nobody moved it yet.

[Rikafip]

have there been any confirmation if Lauda was a she or he or it?
Maybe she confirmed it here:

https://bitcointalk.org/index.php?topic=5098579.msg49276971#msg49276971

Lauda is "he" and anyone thinking otherwise is just fooling themselves. I guess people like to think that Lauda was "she" as we lack females in crypto and he was amused by people guessing his gender. After all, there is an old rule that says that on the Internet everyone is male until proven otherwise.

Gonna quote one of my previous posts why I have no doubts about Lauda's gender and I think that pretty much goes for everyone else that understands Croatian.

It is unknown whether Lauda is male or female, or what age Lauda was.  I say “she”, because I think that Lauda had feminine behaviour.  But she refused to disclose all such information, for reason of privacy.  I myself asked her many personal questions.  All that she would say was, “I’m a cat.”

All those that understand Croatian/Serbian shouldn't have any doubt whether Lauda is a male or female. Among other things, we have  genders for verbs in past tense and adjectives. In his posts made in Croatian board,  Lauda always used masculine gender. I remember some time ago I was so bored that I actually tried to find posts where he used feminine gender, to no avail.

Just an example from one of his posts. Adjectives and verbs are bolded, all masculine gender.

Razumio sam sada.

Ne bih rekao ali u svakom slucaju ne bih ti preporucio.

Da nisam procitao ovu temu ne bih ni skontao . Zauzet sam nesto trenutno, ali bar ima srece s ovom cijenom.

This is how it would look like if it was written using feminine gender

Razumila/Razumjela sam sada.

Ne bih rekla ali u svakom slucaju ne bih ti preporucila.

Da nisam procitala ovu temu ne bih ni skontala . Zauzeta sam nesto trenutno, ali bar ima srece s ovom cijenom.

Maybe Lauda wanted to hide his gender right from the beginning, but somehow I think that he had just a bit of fun with people guessing it because of his name ends with an "a" or whatever else started all that, even though when I heard his name for the first time it didn't sound as a female name since it reminded me of a famous Austrian F1 driver Niki Lauda.

[nullius]

someone doubled the prize money

Also, there is some traffic related to this address on testnet3.

😺

I myself could reproduce the private key from scratch, using only the information that is publicly available on the blockchain.

I have made it so that the puzzle can be solved with any computer that could run Bitcoin Core.

I could be wrong, but if the whole challenge can be completed with Bitcoin Core, [...]

Clarification:  I didn’t say that it could be solved with Bitcoin Core.  In the context of discussing hardware requirements, I said that it can be solved with any computer that could run Bitcoin Core.  It my way of saying that you don’t need fancy, expensive hardware for this.  I love how Core has kept it possible to Be Your Own Bank on inexpensive devices.  Poor people are welcome to try this.  You can solve it just as well on a Raspberry Pi as on a many-core Xeon.  Bitcoin is for everyone!

People with GPU-farms can grind on it however they want, as much as they want.  It will not help.  Finesse, not force will solve this.  The key is cryptographically as “strong” as any Bitcoin key—but I leaked information about how to reconstruct it.  Security through obscurity:  Can you find the clues hidden in plain sight?  Even if you can find them, can you guess my thought process for putting it all together?

Reconstructing the key will require at least intermediate-level Bitcoin knowledge—not real wizardry, but definitely not newbie-level.  If I created a txid that starts with 36 zero-bits, I obviously wrote some custom code for this.  (Call that “Proof of Something-More-Than-Meets-The-Eye”.)  Retrieving the money would be easier, but at least a modicum of skill and effort will be needed.

[...ideas for how to solve it...]

I will not give an further hints. 😼

So it is not yet taken, because it is based on "security through obscurity".

That part, in itself, is entirely correct.

Another question is if that challenge will be upgraded to Taproot? Because if it is really based on HMAC-SHA256 or things like that, then it could be as well based on Taproot, where there are endless possibilities for a brainwallet TapScript, exactly in the same way, as there are endless possibilities, when it comes to signing some transaction. As I said, it is based on obscurity, and that's the only reason why nobody moved it yet.

I have no intention to “upgrade” this puzzle, but I am excited by some of the possibilities offered by Taproot for other purposes.

Earlier in this thread, I quoted a post in which Lauda presented a female image and spoke of her “husband”, in a context where I think that she was probably joking; see also my take on it.  Other forum members have dug up posts where Lauda seemed to indicate or imply being a man.  I think it’s likely that the apparent contradictions were not unintentional.

Lauda is "he" and anyone thinking otherwise is just fooling themselves. [...old posts indicating that Lauda was a man...]

nullius is lauda. That is very clear. Anyone who does not see this is simply closing their eyes.

With apologies to Quickseller, who is a gentleman.  Sorry, it is just too funny here.

LOL, at least I admit that I don’t know.  You are so sure.  I am sure that you know less than I do—and I don’t know.

Flip a coin, pick a pronoun, and stick to it.

[DireWolfM14]

I don't think Lauda is gone.  I believe he's still around and has done a great job keeping his new identity from being discovered.  Even at the end it seemed to me that he loved this forum, and loved it too much to just give up.  The "goodbye" post was surprising only in the way that I should have expected it.

I think the "Lauda" account just got too burdensome with all the baggage.  Most people would find all that drama distracting, I know I would.  Maybe he just wanted to start fresh, without all the distractions.

[Rikafip]

LOL, at least I admit that I don’t know.  You are so sure.  I am sure that you know less than I do—and I don’t know.

Since Lauda wrote in masculine gender, its logical to assume that he is male and refer to him as such. Why would I refer to him as "she" when he obviously wanted to be perceived as a male while being active in Croatian board? Things are often simple but people tend to overthink.

[nullius]

Well, here go the conspiracy theories:

I don't think Lauda is gone.  I believe he's still around and has done a great job keeping his new identity from being discovered.  Even at the end it seemed to me that he loved this forum, and loved it too much to just give up.  The "goodbye" post was surprising only in the way that I should have expected it.

I think the "Lauda" account just got too burdensome with all the baggage.  Most people would find all that drama distracting, I know I would.  Maybe he just wanted to start fresh, without all the distractions.

I am sure not—this, I am sure about.  (Unless I am Lauda’s alt, as QS, TS, and others have claimed at various times.  I have never denied it.  Wouldn’t it be lulzy if they were right!)

People who believe that this forum is some be-all, end-all that people can never leave need to gain some perspective on life.  It is an Internet forum.  Why can nobody choose to leave this forum and never, ever return?  Those who believe it is impossible to leave must surely be projecting, in ways that I do not care to speculate about.  (Jay? )  And to interpret her emphatic declaration she left as confirming that she secretly stayed is conspiracy-theory tier pretzel-logic.

For anyone who has a unique personality in both style and substance, restarting with a new account is not a realistic possibility.  Mediocrities who never attain a high profile could easily hide in the crowd; those who are otherwise never can.  The risk of being outed is too high.  In case you have not noticed, this forum is infested with dweebs with no lives, who are obsessed with speculating on the “real” identities of innocent new accounts that obviously aren’t really newbies.  I have been intending to make a general thread on this exact topic, from my concerns as a privacy activist—and from my musing that sadly, I believe it would be infeasible for Satoshi himself to return to his own forum in a different guise.

Furthermore, based on my private conversations with Lauda at the time she left, I am morally certain that she will never return to this forum.  Sufficiently certain that I will immediately issue negative trust feedback and raise a Type-1 flag on any account that claims to be Lauda.

And furthermore, her departure was unsurprising to anyone who knew her as you did not.  I was shocked when it happened, and deeply disturbed by how it happened.  I fear that something may have gone very wrong.  But I had long been expecting her departure—well, I had been expecting some sort of a retirement party, a happy event.  The cat devoted a big chunk of her life to this forum; she did not want to spend the rest of her life on it.  At some point, she would inevitably move on.


The notion that Lauda may return with a new account is not new.  It was raised almost immediately.  As a final duty to her here, I must firmly squelch it.  Lauda did her best to burn all her bridges here, for the express purpose of preventing any scams that potentially may attempt to exploit her reputation.

Rumours of Lauda sightings would open the way to Faketoshi-style impersonations, which could be highly profitable:  I would trust Lauda with any amount of money, and I am far from the only one!  An impersonator could play off the type of thinking that you are setting up, by “reluctantly” letting himself be “discovered” as Lauda.  It is a usual way for such a scam; recall that from the start, before he switched to demanding that everyone believe him, Craig Wright pretended to be reluctant about “admitting” that he was Satoshi.

Lauda will NOT be returning under a new account.

no option but to leave the forum permanently.

Quite sad. We've barely interacted, but you were on my trust list for obvious reasons.
It's a big loss for the forum. Maybe you'll "reincarnate" under another user and continue where you left off (one can hope). It would be still a loss, but at least it'll be temporary, until your voice will be strong enough again.

Much though I wish that I could share in that dream, no.  Lauda is gone from this forum.  She will not be returning.  I trust her word, as expressed in OP here.

As Lauda’s admitted fan, I respect and appreciate your sentiment; but please do not sow the seeds of what her OP hereby so sought to avoid.  This type of speculation could open the way for the scam of a Lauda pretender, in a more subtle way.

LOL, at least I admit that I don’t know.  You are so sure.  I am sure that you know less than I do—and I don’t know.

Since Lauda wrote in masculine gender, its logical to assume that he is male and refer to him as such. Why would I refer to him as "she" when he obviously wanted to be perceived as a male while being active in Croatian board? Things are often simple but people tend to overthink.

That’s a claim far away from your prior post, whereby you said that anyone who disagreed was fooling themselves.

By analogy, I usually write with British spelling.  I am perfectly capable of consciously switching to American spelling—and of mixing the two, not from confusion, but from a desire to cause confusion.  (Satoshi did the same thing, with Brit/Murican spelling; there exist some statistical analyses this.)  I also sometimes purposely switch or mix regional vocabulary (“petrol”/“gas”), idioms, etc.

Since I write with British spelling, it is logical to assume that I am British or Commonwealth, and to refer to me as such—yes?

Although English lacks the grammatical nuances of the Croatian language, I am sure that I could consistently make myself seem either masculine or feminine in any language that I know.  I am sure, at least, that Lauda was smart enough to pull off such a thing if he/she so desired.

You call him a “he”.  I call her a “she”.  No problem.  Neither of us knows.  I have also seen theories that the correct answer is “they”, i.e., a group operating the Lauda account.  I think that is very unlikely; but I don’t know for certain about that, either.

[garlonicon]

If I created a txid that starts with 36 zero-bits, I obviously wrote some custom code for this.

Of course. The same did the guy in testnet3 that mined those transactions with nine leading zero bits. So now we know that people can mine transactions, but still, the whole solution is unknown.

I will not give an further hints.

Of course. Keep your secrets, that's the whole fun to guess all of that. Also I know that you wrote exactly that sentence before. So it is like OP_CODESEPARATOR: the secret part of the script is already hidden, only the remaining part is visible.

But I still wonder, if it is possible to make it easier in the future, by revealing some hints in decentralized way (also, some sighashes can be used to make it an incentive, like "I will reveal you my public key, only if you put N coins to this challenge", it is possible to make it so that coins will move only when both parties will meet those conditions). For example, spending "OP_HASH160 5ab6db66fb0dd08ecb238f07141ffea56189552d OP_EQUALVERIFY OP_CODESEPARATOR <newPublicKey> OP_CHECKSIG" could reveal the public key for the puzzle in a trustless way. And later, any 2-of-2 multisig could reveal that the private key for the puzzle is reachable. Because now, you know, only some random hash is visible. It could be a trap address. A public key could be unreachable or invalid, or a private key could be provably unknown. Or maybe everything was created as a result of SIGHASH_SINGLE bug, or a tricky signature: https://bitcointalk.org/index.php?topic=5373858.0. Nobody knows, and nobody can trust any future hints, that is clear. But even if there will be some disinformation, it can be still used to make more challenges.

For example, I can tell you it is not based on sethdseed, as far as I checked. But it seems like another nice challenge, to start from sethdseed true "KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qYjgd9M7rFU73sVHnoWn", then do some tricks, and reach some interesting brainwallet. For example, here it will be always bc1qvl6xr6th5v7qafuclkkvv67w803hw5zk5g60xu, and then, it is possible to deterministically do many tricks.

[The Sceptical Chymist]

Flip a coin, pick a pronoun, and stick to it.

[/quote]Ha ha!!  I thought you were gone, nullius.  Admittedly I haven't checked your post history to verify if you'd been gone, but it seems like forever since I've seen you post.  Happy to see that at least a few strong & crazy personalities are still around these days.

Theymos referred to Lauda as a "he" a while back, though damned if I could find a reference for that as it might have been via PM.  If anyone would know Lauda's gender, it'd probably be The Boss himself....but seeing as how Lauda was so careful in concealing his/her/whatever's identity, even Theymos might not have known.

I don't think Lauda is gone.  I believe he's still around and has done a great job keeping his new identity from being discovered. 

Could be.  I always thought nullius was Lauda's alt, but the sheer amount of writing that one person would have to do to pull that off would be astounding to say the least, so I gave up on that little theory.  Not a small part of me wishes Lauda, Vod, TMAN, and probably a few other members that aren't coming to mind would return simultaneously.  That would be a trip. 

Hell, even if they staggered their reappearances, it'd be amazing.

[nullius]

garlonicon, thanks for engaging in the type of discussion that I’d hoped to incite when I made the puzzle:

If I created a txid that starts with 36 zero-bits, I obviously wrote some custom code for this.

Of course. The same did the guy in testnet3 that mined those transactions with nine leading zero bits. So now we know that people can mine transactions, but still, the whole solution is unknown.

I am curious.  Would you please point me to the txids?  I have not been running a testnet node (or for personal reasons, much of anything lately).  I’d love to see this.

The thirty-six leading zero bits (nine zero nibbles) denote when I decided to stop grinding.  On my ancient junk-heap hardware, it took me days of almost overheating my computer to get up to 36 zeroes.  However I did it, I could have kept going to grind out more zeroes in the manner of any other POW.  I will not comment on how (or even whether) that relates to the puzzle’s solution; it may lead the way to the solution, or it be a red herring. 😼

Someday, this “mining” of txids may make for an interesting thread in the development forum.  Or here!  I have many related ideas, which may be useful in various ways.

I’m not sure:  Was that the first time anyone had ever done this?  Need to scan the chain for analysis...

I will not give an further hints.

Of course. Keep your secrets, that's the whole fun to guess all of that. Also I know that you wrote exactly that sentence before. So it is like OP_CODESEPARATOR: the secret part of the script is already hidden, only the remaining part is visible.

When I published the puzzle, I thought that either it would be solved very quickly, or it would never be solved.  It did not seem to get much attention, at first—perhaps due to the low funding amount.  Now that it seems to be getting more attention, I am deeply curious about whether anyone may crack it.  If nobody does, then perhaps I may use a similar method to create and back up my personal wallet—lulz!

Could this be like the Beale ciphers?

I want to give it some time.  Get more people curious.  Difficult puzzles are more fun, but insoluble puzzles not so much—we’ll see.

Thanks for your interest here, and good luck with whatever attempts you may be making.

In memory of Kitty! 😺

Ha ha!!  I thought you were gone, nullius.

I was, for over a year.  I reluctantly “woke” my account on 29 June for the primary purpose of addressing some badness which came to my attention, which I could not in conscience ignore; that is not yet done, alas.  By coincidence, some Lauda-related things arose.  Well, when did I ever miss a chance to talk about Lauda?  LOL.

Theymos referred to Lauda as a "he" a while back, though damned if I could find a reference for that as it might have been via PM.

There was also a rumour that theymos had an intimate relationship with Lauda.  Lauda herself referenced this, in a joking kind of semi-sarcastic way.  (Best link I found on a brief search; I recall some better ones.)  So, take all these things with a grain of salt.

I always thought nullius was Lauda's alt, but the sheer amount of writing that one person would have to do to pull that off would be astounding to say the least, so I gave up on that little theory.

Lauda did seem to be everywhere at once, all the time.  And I have never denied it.  WHY DON’T I DENY IT?  ;-)

[PrimeNumber7]

I am pretty sure that the two have not met in person, assuming they are different people.

To this day, I have never admitted or denied the allegations that I am Lauda’s sockpuppet.  That was a popular refrain in some quarters, in 2018 and in early 2020.  No comment.  My refusal to answer such questions is a personal policy, which I have rarely ever broken for any reason whatsoever.

That is a good policy. However I believe you have said some things to me that would only be possible if you were in fact two different people. 

I think the "Lauda" account just got too burdensome with all the baggage.  Most people would find all that drama distracting, I know I would.  Maybe he just wanted to start fresh, without all the distractions.

The "Lauda" account attracted a lot of attention. Lauda was someone who clearly wanted his privacy, and privacy is difficult when you receive that level of attention.

[icopress]

Guys, keep in mind that Lauda's telegram account has a new owner now. 

A year and a half after I blocked him, the account was deleted, after which someone took over this username.

In addition to leaving the forum for good, Lauda also deleted his Telegram account, (as it turned out). To prevent anyone from being tempted to use this username for fraudulent purposes, I have re-registered this username, (let someone quote this post).

• I registered a new account, set a @GrumpyKitty and threw away the sim card.
• I have set the maximum privacy settings (for calls, chats, etc.).
• The account will be automatically deleted in at least a year, (I have set the maximum time range).
• I set an additional password and logged out.

If still needed, contact me on telegram: @GrumpyKitty.

[nullius]

Guys, keep in mind that Lauda's telegram account has a new owner now. 

A year and a half after I blocked him, the account was deleted, after which someone took over this username.

That is worrisome, if there is any fraudulent intent.  “Grumpy Cat” is a meme, so I hope that someone grabbing “GrumpyKitty” is only a coincidence? 🙀

When Lauda stopped using that name on Telegram, she asked theymos to remove her “GrumpyKitty” custom title.  I cannot now find an appropriate reference; IIRC, the relevant thread got trashed for reasons unknown to me.

Suffice it to say that Lauda is not on Telegram.  Or anywhere.  Don’t get scammed!

[garlonicon]

Would you please point me to the txids?

with nine leading zero bits

Sorry, bytes nibbles (4-bits) of course. There are more transactions, but you can start with them:
https://mempool.space/testnet/tx/0000000009e6f27e34e9d5e17df63758375195eb76b46daf0327b4aba151bfb4
https://mempool.space/testnet/tx/0000000005771270ab7be0d9dc5358048aad0e003c6482819438fd9a61b80841

it may lead the way to the solution, or it be a red herring

In my opinion it is just a nice trick, but I could be wrong. Also note that it is possible to use sequence number or locktime to make it easier. For example, it is possible to set sequence number to 0xffffffff, then locktime is ignored, and can be used as a nonce, just like in a real mining, only the total size is different. But even if someone has an ASIC miner, then it is possible to choose the right transaction size, to optimize it for a specific hardware.

Someday, this “mining” of txids may make for an interesting thread in the development forum.

When it comes to transaction mining, it is just a nice trick, but nothing else is behind that. The better way would be to mine on top of the latest block, then by using Merged Mining, it could be possible to reuse Bitcoin Proof of Work, and make the whole network stronger. And then, it could be a part of decentralized mining, where people could receive N times less coins for mining N times easier block headers. In this way, CPU mining could be used to get a single satoshis or millisatoshis discount, when using Lightning Network.

Was that the first time anyone had ever done this?

Of course not. See this testnet3 transaction: https://mempool.space/testnet/tx/16fb1c624b3658c78630c39f1c33e8f3dbdb71373f33eb22c6abe4405c0815bc
You can try to grab some zero satoshi test coins by re-mining satoshi's blocks. And there are more such transactions.

[nullius]

000000000fdf0c619cd8e0d512c7e2c0da5a5808e60f12f1e0d01522d2986a51
The nonexistent cat is memorialized on the Bitcoin blockchain forever.

Free images of Lauda!

Would you please point me to the txids?

with nine leading zero bits

Sorry, bytes nibbles (4-bits) of course. There are more transactions, but you can start with them:
https://mempool.space/testnet/tx/0000000009e6f27e34e9d5e17df63758375195eb76b46daf0327b4aba151bfb4
https://mempool.space/testnet/tx/0000000005771270ab7be0d9dc5358048aad0e003c6482819438fd9a61b80841

Cool.  Thanks.  I’d much appreciate more.

In my opinion it is just a nice trick, but I could be wrong. [...]

Someday, this “mining” of txids may make for an interesting thread in the development forum.

When it comes to transaction mining, it is just a nice trick, but nothing else is behind that.

When I indicate that I have some practical usage in mind, I probably do.  Beyond a neat trick.  But I may want to keep it a trade secret.  Note that what I was doing was probably more complicated than you guessed.

112f4a306f8bbe39270b0f1070751038fcf01f4a5eca42277a83e7ab3791afd5

Was that the first time anyone had ever done this?

Of course not. See this testnet3 transaction: https://mempool.space/testnet/tx/16fb1c624b3658c78630c39f1c33e8f3dbdb71373f33eb22c6abe4405c0815bc
You can try to grab some zero satoshi test coins by re-mining satoshi's blocks. And there are more such transactions.

That txid obviously is not so; and at a glance, I don’t see any related txids with too many leading zeroes to be coincidental.

I meant:  Was 000000000fdf0c619cd8e0d512c7e2c0da5a5808e60f12f1e0d01522d2986a51 the first time that anyone had ever mined a POW txid with many leading zeroes, or any other easily recognizable pattern?  Especially on Bitcoin mainnet!

If my Kitty tx for Lauda was the first, I would purr.  (Also, if it was the first to embed a cat emoji in OP_RETURN.)  I was not even much thinking that way last year—just trying to make something fun and challenging in Lauda’s memory, like the sporting games that the Greeks played at the funerals for heroes in classical antiquity. 😺

[DireWolfM14]

Not a small part of me wishes Lauda, Vod, TMAN, and probably a few other members that aren't coming to mind would return

I never really clicked with Lauda, but I do miss his influence.  At least one member who's been absent and missed has recently returned; nutildah is back.

I miss Vod and TMAN.  I'm convinced that TMAN was IRL John Wayne's alt, but age finally caught up with him.

I also miss sparring with Tecshare.

[garlonicon]

That txid obviously is not so

Look at transaction outputs instead. And notice that we still miss OP_CAT to make it complete. We miss it, because it can be used to do quines, and other naughty stuff, for the same reason OP_SUBSTR is disabled, also for example OP_AND, which can be used to emulate OP_CAT. Because it is possible to push some prefix, some postfix, ask OP_CAT to play with this wool, and then demand equality by using OP_HASH256 and OP_EQUAL. In general, "OP_HASH256 <someHash> OP_EQUAL" can be used for block header (always 80 bytes), merkle proof (always 64 bytes), or for a transaction (any size). Using OP_SIZE is the only practical way to distinguish it, because checking more things require more complicated script, and that costs more precious satoshis.

But I may want to keep it a trade secret.  Note that what I was doing was probably more complicated than you guessed.

There are not that many things you can do with that. I can imagine the whole merkle tree, filled with low transaction hashes. And what's next? Then you can for example split the coinbase between them, based on the number of zeroes they contain. Or you can provide someone a transaction hash, and allow some tricks by exploiting length extension attack, if you need that for OP_CODESEPARATOR scripts. Then, someone can agree to sign something, without knowing the whole script, because it is about using OP_CODESEPARATOR to prepend some unknown script into that: https://bitcointalk.org/index.php?topic=5375893.0

[nullius]

And notice that we still miss OP_CAT to make it complete. We miss it, because it can be used to do quines, and other naughty stuff, [...]

I see what you did there.  That describes me perfectly. 😿

Thank you for the interesting technical discussion.  Any new ideas for how to solve the puzzle?  I won’t give any more hints; and I don’t want to pry about anything you are secretly thinking may let you win.  Nonetheless, I myself am a curious cat.

[garlonicon]

Any new ideas for how to solve the puzzle?

That's the problem: there are too many options. So, I have many ideas, I thought about sethdseed "privkeyForBrainwallet", because it is simple, and because it meets all conditions. But still, there are endless options that can be used as a privkey. Every time when there are some 32 bytes, then you can put there any hash, so the whole process can be unsafe, but the whole security comes from the algorithm. And if it is needed to mine something, just to get some 32-bit offset (or rather 36-bit offset), then it is even harder, because then every new way costs a lot of hashing, even if it is solvable by any CPU.

Also, when it comes to mining transactions, it can be just some kind of timelock: https://www.gwern.net/Self-decrypting-files