Bitcoin, Byzantine generals and 51% attack

[Come-from-Beyond]

It seems to be a well-known fact that Bitcoin solves Byzantine Generals' Problem. At least I quite often see words "Bitcoin" and "Byzantine generals" together. But some numbers don't add up. We talk about 51% attack while Lamport talks about 66% ("...this problem is solvable if and only if more than two-thirds..."). What is wrong?

[tl121]

It seems to be a well-known fact that Bitcoin solves Byzantine Generals' Problem. At least I quite often see words "Bitcoin" and "Byzantine generals" together. But some numbers don't add up. We talk about 51% attack while Lamport talks about 66% ("...this problem is solvable if and only if more than two-thirds..."). What is wrong?

1.  There may be other attacks on Bitcoin that require less than 51%.
2.  The problems that Bitcoin and Lamport address are related but not identical.

[Bitcoin Magazine]

i read about that shit in 2009 and i don't give a shit.  it's all bullshit.  a text background on a white screen

[brooklynbtc]

i read about that shit in 2009 and i don't give a shit.  it's all bullshit.  a text background on a white screen

Best solution to external threats and FUD is always head-in-sand. What you can't see or hear, won't hurt you.

[LiQio]

Watching. Eager to learn. Bump.

[inBitweTrust]

("...this problem is solvable if and only if more than two-thirds..."). What is wrong?

read the following line ....

With unforgeable written messages, the problem is solvable for any number of generals and possible traitors.

2/3rds deals with communication between untrusted parties where unforgeable written messages aren't in use. Of course Bitcoin messages can be forgeable, but the genius of the system is both the consensus mechanism and the incentive structure both discourage users from doing so and make it increasing more difficult to do so with time.

Thus Bitcoin does solve the Byzantine fault tolerance dilemma until a "51% attack" occurs as the authentic blockchain is trusted until such an event occurs.

[Come-from-Beyond]

read the following line ....

With unforgeable written messages, the problem is solvable for any number of generals and possible traitors.

2/3rds deals with communication between untrusted parties where unforgeable written messages aren't in use. Of course Bitcoin messages can be forgeable, but the genius of the system is both the consensus mechanism and the incentive structure both discourage users from doing so and make it increasing more difficult to do so with time.

Thus Bitcoin does solve the Byzantine fault tolerance dilemma until a "51% attack" occurs as the authentic blockchain is trusted until such an event occurs.

Thank you.

[devphp]

Thank you.

What do you mean? )

[Come-from-Beyond]

What do you mean? )

I mean exactly what I wrote.

[inBitweTrust]

What do you mean? )

I mean exactly what I wrote.

Your welcome and thank you for being so genuine and honest. This post is evidence that despite the antagonism between different projects we all have similar motivations towards finding the truth and working towards a better future.

I want to further elaborate on one possible objection people may have. Some may suggest that if Bitcoin is dependent upon trusting the validity of the blockchain upon solving the Byzantine generals dilemma it may refute the whole notion of ultimate trust as a 51% attack can happen at any moment. Unlike with multiple messengers or couriers in the original dilemma, blockchain based crypto-currencuies use of a public ledger system make immediate acknowledgement and demarcate the attack so the "generals" or users can identify if the message is to be trusted or not. Before a 51% attack occurs you can be probabilistically sure to a certain degree based upon the amount of nodes and time passed that a transaction is valid. If a 51% attack occurs it merely shifts the recognition of these false transactions until shortly after they occur until the attacker is dealt with.

[Bit N Roll]

i read about that shit in 2009 and i don't give a shit.  it's all bullshit.  a text background on a white screen

Why is it bullshit?

[inBitweTrust]

i read about that shit in 2009 and i don't give a shit.  it's all bullshit.  a text background on a white screen

Why is it bullshit?

He/she is merely a troll that is best ignored.