Forwarded from Phil Wilson
Hal's website is where proof-of-work was first described clearly enough.
Forwarded from Phil Wilson
If anyone is into the Bitcoin tech ( and counterparty is on top of that tech ) then Hal's website is a much-read
Forwarded from Phil Wilson
You could effectively remove every single reference in the Bitcoin white-paper and replace it with a link to Hal's website.
It's that important.
It's that important.
Forwarded from Phil Wilson
Forwarded from BitCoin History (@RamonQuesada)
leparisien.fr
RECIT. Qui était Hal Finney, l'homme qui reçut les premiers bitcoins ?
LE PARISIEN WEEK-END. Il y a neuf ans, la première transaction en bitcoins, dont la cote flambe actuellement, était réalisée. Si l’identité de l’inventeur de cette monnaie numérique reste mystérieuse, celle de son premier utilisateur est connue : Hal Finney…
Forwarded from Ramon Quesada - News 🌷 (@RamonQuesada)
Una joya historica del 2009, espero que conozcais a Hal Finney la primera persona que recibio una transaccion de Satoshi. https://twitter.com/halfin/status/1153096538
X (formerly Twitter)
halfin (@halfin) on X
Thinking about how to reduce CO2 emissions from a widespread Bitcoin implementation
Forwarded from José Antonio Bravo Mateu No doy consejos de inversión
Satoshi es Hal Finney, es Wei Dai, es Adam Back, es Nick Szabo, y es toda la gente que desde finales de los 70 estaba trabajando la criptografía de doble entrada para buscar soluciones útiles
Forwarded from Ramon Quesada - News 🌷 (@RamonQuesada)
What is a Finney attack? Extra points for explaining its purpose, the prerequisites for it to be possible, how the attack can be performed and the origin of the name "Finney attack".
asked Oct 3 '12 at 9:03
The Finney attack is named after Hal Finney, who suggested it in this comment. (Hal happens to be the first recipient of a Bitcoin transaction, and the first person to comment on the release of the Bitcoin source code.)
It is a double spending attack with the following features:
It only works if the merchant accepts unconfirmed transactions.
It still works, however, if the merchant waits a few seconds to verify that everyone in the network agrees he was paid.
It requires the attacker to be mining and controlling the content of his blocks; however, he can in theory do this with any hashrate, in particular significantly less than 50% of the network hashrate.
It proceeds as follows:
The attacker mines blocks normally; in the block he is trying to find, he includes a transaction which sends some of his coins back to himself, without broadcasting this transaction.
When he finds a block, he does not broadcast it; instead, he sends the same coins to a merchant for some goods or service.
After the merchants accepts the payment and irreversibly provides the service, the attacker broadcasts his block; the transaction that sends the coins to himself, included in this block, will override the unconfirmed payment to the merchant.
If the time from finding the block until the attacker sends payment and the merchant accepts it is t, and the average time to find a block is T, there is a probability of t/T that another block will be found on the network in this time; in this case the attack will fail, and the attacker will lose the block reward of B.
This means that the average cost of attempting the attack is about (t/T) * B; as a rule of thumb the merchant should wait at least t=V*T/B (V is the value of the transaction), to make sure that trying to carry out this attack against him isn't profitable; this may not be sufficient though, as a nimble attacker can use the same block for multiple attacks, potentially gaining the total of their value.
Clearly, the lower the attacker's hashrate, the less opportunities he has to carry out the attack. If the attack is for obtaining some illiquid good, it is difficult to make the need for this good coincide with finding a block. If the attack is for obtaining something liquid (e.g. exchanging bitcoins for other money), an opportunity is ever-present but the merchant is likely to require a few confirmations. This makes the attack difficult to use in practice.
https://bitcoin.stackexchange.com/questions/4942/what-is-a-finney-attack
asked Oct 3 '12 at 9:03
The Finney attack is named after Hal Finney, who suggested it in this comment. (Hal happens to be the first recipient of a Bitcoin transaction, and the first person to comment on the release of the Bitcoin source code.)
It is a double spending attack with the following features:
It only works if the merchant accepts unconfirmed transactions.
It still works, however, if the merchant waits a few seconds to verify that everyone in the network agrees he was paid.
It requires the attacker to be mining and controlling the content of his blocks; however, he can in theory do this with any hashrate, in particular significantly less than 50% of the network hashrate.
It proceeds as follows:
The attacker mines blocks normally; in the block he is trying to find, he includes a transaction which sends some of his coins back to himself, without broadcasting this transaction.
When he finds a block, he does not broadcast it; instead, he sends the same coins to a merchant for some goods or service.
After the merchants accepts the payment and irreversibly provides the service, the attacker broadcasts his block; the transaction that sends the coins to himself, included in this block, will override the unconfirmed payment to the merchant.
If the time from finding the block until the attacker sends payment and the merchant accepts it is t, and the average time to find a block is T, there is a probability of t/T that another block will be found on the network in this time; in this case the attack will fail, and the attacker will lose the block reward of B.
This means that the average cost of attempting the attack is about (t/T) * B; as a rule of thumb the merchant should wait at least t=V*T/B (V is the value of the transaction), to make sure that trying to carry out this attack against him isn't profitable; this may not be sufficient though, as a nimble attacker can use the same block for multiple attacks, potentially gaining the total of their value.
Clearly, the lower the attacker's hashrate, the less opportunities he has to carry out the attack. If the attack is for obtaining some illiquid good, it is difficult to make the need for this good coincide with finding a block. If the attack is for obtaining something liquid (e.g. exchanging bitcoins for other money), an opportunity is ever-present but the merchant is likely to require a few confirmations. This makes the attack difficult to use in practice.
https://bitcoin.stackexchange.com/questions/4942/what-is-a-finney-attack
Bitcoin Stack Exchange
What is a Finney attack?
What is a Finney attack? Extra points for explaining its purpose, the prerequisites for it to be possible, how the attack can be performed and the origin of the name "Finney attack".
Forwarded from José Antonio Bravo Mateu No doy consejos de inversión
Fue Hal Finney el que dijo que un atacante malicioso podría incluir una transacción de A a B (direcciones que controla) en un bloque, y meter en el mismo bloque una transacción de A a C (que no controla). Si aceptásemos 0 confirmaciones, la transacción de A a C la aceptarías pero nunca se produciría. Eso es lo que se conoce como "ataque Finney" y por eso se requiere al menos una confirmación (y lo de las 0-conf es una boutade)
Forwarded from Ramon Quesada - News 🌷 (@RamonQuesada)
Hal es una de las personas que mas admiro en el criptomundo, quien recibió la primera transacción de Satoshi Nakamoto y le ayudó en los inicios, a mejorar el codigo de Bitcoin, Actualmente criogenizado, a la espera de una cura futura para el ELA.
Who is Hal Finney? Was He the Real Man Behind Bitcoin?
https://101blockchains.com/who-is-hal-finney-bitcoin/
Who is Hal Finney? Was He the Real Man Behind Bitcoin?
https://101blockchains.com/who-is-hal-finney-bitcoin/
101 Blockchains
Who is Hal Finney? Was He the Real Man Behind Bitcoin?
In the modern world, everything is moving fast as the technology around us advances at a rapid pace. One perfect example of the modern technology and its
¿Se pueden encontrar pistas sobre los primeros misterios de Bitcoin en un cerebro crioconservado? - http://goo.gl/alerts/a5E9B
Criptomonedas e ICOs
¿Se pueden encontrar pistas sobre los primeros misterios de Bitcoin en un cerebro crioconservado? | Criptomonedas e ICOs
Se ha especulado a lo largo de los años sobre si el último desarrollador de software, Hal Finney, era en realidad Satoshi Nakamoto. Algunas personas se preguntan si tenía alguna conexión con los 700,000 bitcoins extraídos en los primeros días del protocolo.
"Hal was far more the anarchist than I could ever imagine. I had many in my circle who were anarchist in nature, and I didn’t really think about the utopian goals they held and problems they could cause later on. Hal wanted people to run nodes early on. He is the reason that we had a block cap. I knew that I should have fought back and not have allowed it."
https://medium.com/@craig_10243/hello-dave-330c164a4aad
https://medium.com/@craig_10243/hello-dave-330c164a4aad
Medium
Hello Dave…
Hal Finney was an amazing man in many ways. Without him, Bitcoin would not exist today. Hal is a far better coder than I will ever hope...
"One experimental "information market" is BlackNet, a system which appeared in 1993 and which allows fully-anonymous, two-way exchanges of information of all sorts. There are reports that U.S. authorities have investigated this because of its presence on networks at Defense Department research labs. Not much they can do about it, of course, and more such entities are expected."
12 Acknowledgments
My thanks to my colleagues in the Cypherpunks group, all 700 of them, past or present. Well over 100 megabytes of list traffic has passed through he Cypherpunks mailing list, so there have been a lot of stimulating ideas. But especially my appreciation goes to Eric Hughes, Sandy Sandfort, Duncan Frissell, Hal Finney, Perry Metzger, Nick Szabo, John Gilmore, Whit Diffie, Carl Ellison, Bill Stewart, and Harry Bartholomew. ..."
http://groups.csail.mit.edu/mac/classes/6.805/articles/crypto/cypherpunks/may-virtual-comm.html
12 Acknowledgments
My thanks to my colleagues in the Cypherpunks group, all 700 of them, past or present. Well over 100 megabytes of list traffic has passed through he Cypherpunks mailing list, so there have been a lot of stimulating ideas. But especially my appreciation goes to Eric Hughes, Sandy Sandfort, Duncan Frissell, Hal Finney, Perry Metzger, Nick Szabo, John Gilmore, Whit Diffie, Carl Ellison, Bill Stewart, and Harry Bartholomew. ..."
http://groups.csail.mit.edu/mac/classes/6.805/articles/crypto/cypherpunks/may-virtual-comm.html
Untraceable Digital Cash, Information Markets, and BlackNet
("Governmental and Social Implications of Digital Money" panel at CFP '97)
Tim May
Corralitos, CA
tcmay@got.net
5. "Anyone a Mint"
Recent work by Ian Goldberg of UC Berkeley, and similar work by Doug Barnes, Hal Finney, and others, makes a truly anonymous digital cash system possible. Goldberg's scheme allows "e-cashiers" and "e-moneychangers" to disintermediate the process and ensure untraceability. Importantly, anyone can essentially become a "mint" of digital cash...."
http://osaka.law.miami.edu/~froomkin/articles/tcmay.htm
("Governmental and Social Implications of Digital Money" panel at CFP '97)
Tim May
Corralitos, CA
tcmay@got.net
5. "Anyone a Mint"
Recent work by Ian Goldberg of UC Berkeley, and similar work by Doug Barnes, Hal Finney, and others, makes a truly anonymous digital cash system possible. Goldberg's scheme allows "e-cashiers" and "e-moneychangers" to disintermediate the process and ensure untraceability. Importantly, anyone can essentially become a "mint" of digital cash...."
http://osaka.law.miami.edu/~froomkin/articles/tcmay.htm