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All crypto will eventually be broken. SHA-1 seemed bulletproof a few years ago, and now people are trying to phase it out. If it becomes worth it to break bitc

All crypto will eventually be broken. SHA-1 seemed bulletproof a few years ago, and now people are trying to phase it out. If it becomes worth it to break bitcoin, these vulnerabilities will be used, discovered faster, and likely won't be published before someone uses it to profit off Bitcoin and crashing the price. Bitcoin is priced this high because uneducated people expect it to replace paypal and credit cards but it will never be able to because 1 transaction take 30+ minutes and that is by design. The faster they make transactions take, the higher chance of forgery. Other crypto-currencies that attempt to have faster transactions are simply trading safety for speed.

foota 9y ago
A few? https://www.schneier.com/blog/archives/2005/02/sha1_broken.html https://www.schneier.com/blog/archives/2005/02/sha1_broken.h...
placeybordeaux 9y ago
For a merchant a CC transaction can take up to 30 days. A customer can initiate a charge back any time between when they txed and when they pay their bill. With bitcoin the ~10m+ tx time is a cost, but is in material if you are dealing with either a trusted party or a small amount of $
- codexon 9y ago
  > For a merchant a CC transaction can take up to 30 days. A customer can initiate a charge back any time between when they txed and when they pay their bill. Customers don't care how long a transaction takes for the merchant. Have you ever tried selling anything for bitcoin? Nearly no one will use it even when being told of all the "benefits". They don't want to wait 30+ minutes. When they see they need to give some exchange a scan of their passport and wait 3-5 days to link their bank account, and losing the ability to do a chargeback, they never think about using Bitcoin again.
  - icebraining 9y ago
    FUD much? I never had to give anyone a scan of my passport, or link my bank account.
  - placeybordeaux 9y ago
    I've only bought a couple things with bitcoin, never sold. The current story for bitcoin is pretty sad, largely due to slow adoption and not much of a good story for consumers. The good thing is that bitcoin doesn't have to compete directly with CC companies. There are cases that it solves that CC companies aren't interested in. There's all this concern about price volatility and tx rate, but it's been used continuously in spite of price volatility, and saying no one wants to use bitcoin because there's too many outstanding bitcoin transactions just isn't a serious argument. I care about bitcoin because it is an interesting piece of technology that enables things that weren't possible before. I'll hold bitcoin so long as they don't go to zero, none of the concerns listed about bitcoin that I have heard are serious arguments on why it might go to zero, so I'll hold.
    - bubblethink 9y ago
      >The good thing is that bitcoin doesn't have to compete directly with CC companies. Current CC companies are essentially two products. One is the transaction processing side of things, and the other is the financial + insurance product which protects both parties from fraud, chargebacks etc. Crypto currencies should be able to make transaction processing effectively free. All you need is an insurance product that operates at margins lower than 2-3% (current credit cards).
  - acchow 9y ago
    > They don't want to wait 30+ minutes. So then don't use the bare blockchain for transactions.
- thisisit 9y ago
  This has always been the weakest arguments in favor of bitcoin. It shows people don't understand how actually CC transaction to a merchant works. There is always inherent distrust when money is involved. Hence the ability to charge back a fraudster. Unless of course you deal with a "trusted party" but then the chargeback argument is immaterial, it doesn't matter whether transaction is bitcoin or credit card. Now as for settlement times, sure banks are catching up. Faster is not always better. It always leaves room for fraud. Banks are distrustful on behalf of their account holders. So a particular merchant's bank is not going directly to the customer's bank and demand money. They go to an exchange to ask for a debit and credit. This takes time. Currently bitcoin takes 10m for how many transactions per minute? If we were to talk billions of transactions (not money but actual transactions) flowing through a payment processor and calculate the scale of bitcoin - how much time are we talking about?
goodside 9y ago
> "Other crypto-currencies that attempt to have faster transactions are simply trading safety for speed." This hasn't been true since about 2013. Altcoins don't just twiddle the parameters of BTC anymore. They're all over the place in terms of what algorithms they use, and many of them are clearly better. A lot of what Bitcoin has going for it is inertia, network effects, and price stability. (Yes, compared to alts, Bitcoin is considered stable.)
- codexon 9y ago
  What you say doesn't really disprove my point. Yes you can change to a different algorithm. But the underlying principal is the same. You require participants to spend X time in a problem with no shortcuts. Changing the problem does not allow you to bypass this issue. If you choose a problem that requires less time to calculate, you increase the probability that someone spams the network with fake data. https://en.wikipedia.org/wiki/Proof-of-work_system https://en.wikipedia.org/wiki/Proof-of-work_system You either have a centralized system that can cheaply tell you if something is legitimate, otherwise this is the only way to protect a decentralized system. To my knowledge, there is no altcoin with any significant amount of use that does not use this principal. Please tell me which altcoins do not use this principal.
  - Retric 9y ago
    If you do 1 transaction every minute then someone needs a ~51% attack to "win" after 10 minutes because without that you will not have the longer chain. Having a protocol that can do 1 minute blocks is hard, but not nessisarily less safe because it's number of clocks * computing power that provides safety not the actual effort a block takes.
  - placeybordeaux 9y ago
    > If you choose a problem that requires less time to calculate, you increase the probability that someone spams the network with fake data. No you just decrease the faith you can put into each confirmation. > You either have a centralized system that can cheaply tell you if something is legitimate, otherwise this is the only way to protect a decentralized system. There are some interesting efforts to create systems that work in complement to the main block chain. One complimentary idea is the lightening network which functions by creating channels that only transact of bitcoins that are currently locked out of the bitcoin system. This eliminates the potential for double spending these bitcoins in a tx with a third party. Once you eliminate the potential for double spending you can do just about whatever you want quickly and off chain. The system is set up to be able to be able to resolve all of the txs that happened off chain when the locked up bitcoins are unlocked. Once many of these channels are established you can start to establish a connection. For instance if I have 12 bitcoins in my own wallet I might keep ~1 BTC locked up to a connection to coinbase. From there they may charge a fraction of what the on chain cost for any tx would be. It'd take a regular on chain fee to establish the connnection, but once it is up the fee and latency should drop dramatically.
virtuexru 9y ago
SHA256 is not going to be broken by Moore's law computational improvements in our lifetimes. If it's going to get broken, it'll be by some breakthrough cracking method. An attack that could so thoroughly vanquish SHA256 to bring it within computationally tractable range has a good chance of clobbering SHA512 too. From Satoshi's post on BitcoinTalk: https://bitcointalk.org/index.php?topic=360.msg3520#msg3520 https://bitcointalk.org/index.php?topic=360.msg3520#msg3520

foota 9y ago

A few? https://www.schneier.com/blog/archives/2005/02/sha1_broken.html https://www.schneier.com/blog/archives/2005/02/sha1_broken.h...

placeybordeaux 9y ago

For a merchant a CC transaction can take up to 30 days. A customer can initiate a charge back any time between when they txed and when they pay their bill. With bitcoin the ~10m+ tx time is a cost, but is in material if you are dealing with either a trusted party or a small amount of $

codexon 9y ago
> For a merchant a CC transaction can take up to 30 days. A customer can initiate a charge back any time between when they txed and when they pay their bill. Customers don't care how long a transaction takes for the merchant. Have you ever tried selling anything for bitcoin? Nearly no one will use it even when being told of all the "benefits". They don't want to wait 30+ minutes. When they see they need to give some exchange a scan of their passport and wait 3-5 days to link their bank account, and losing the ability to do a chargeback, they never think about using Bitcoin again.
- icebraining 9y ago
  FUD much? I never had to give anyone a scan of my passport, or link my bank account.
- placeybordeaux 9y ago
  I've only bought a couple things with bitcoin, never sold. The current story for bitcoin is pretty sad, largely due to slow adoption and not much of a good story for consumers. The good thing is that bitcoin doesn't have to compete directly with CC companies. There are cases that it solves that CC companies aren't interested in. There's all this concern about price volatility and tx rate, but it's been used continuously in spite of price volatility, and saying no one wants to use bitcoin because there's too many outstanding bitcoin transactions just isn't a serious argument. I care about bitcoin because it is an interesting piece of technology that enables things that weren't possible before. I'll hold bitcoin so long as they don't go to zero, none of the concerns listed about bitcoin that I have heard are serious arguments on why it might go to zero, so I'll hold.
  - bubblethink 9y ago
    >The good thing is that bitcoin doesn't have to compete directly with CC companies. Current CC companies are essentially two products. One is the transaction processing side of things, and the other is the financial + insurance product which protects both parties from fraud, chargebacks etc. Crypto currencies should be able to make transaction processing effectively free. All you need is an insurance product that operates at margins lower than 2-3% (current credit cards).
- acchow 9y ago
  > They don't want to wait 30+ minutes. So then don't use the bare blockchain for transactions.
thisisit 9y ago
This has always been the weakest arguments in favor of bitcoin. It shows people don't understand how actually CC transaction to a merchant works. There is always inherent distrust when money is involved. Hence the ability to charge back a fraudster. Unless of course you deal with a "trusted party" but then the chargeback argument is immaterial, it doesn't matter whether transaction is bitcoin or credit card. Now as for settlement times, sure banks are catching up. Faster is not always better. It always leaves room for fraud. Banks are distrustful on behalf of their account holders. So a particular merchant's bank is not going directly to the customer's bank and demand money. They go to an exchange to ask for a debit and credit. This takes time. Currently bitcoin takes 10m for how many transactions per minute? If we were to talk billions of transactions (not money but actual transactions) flowing through a payment processor and calculate the scale of bitcoin - how much time are we talking about?

goodside 9y ago

> "Other crypto-currencies that attempt to have faster transactions are simply trading safety for speed." This hasn't been true since about 2013. Altcoins don't just twiddle the parameters of BTC anymore. They're all over the place in terms of what algorithms they use, and many of them are clearly better. A lot of what Bitcoin has going for it is inertia, network effects, and price stability. (Yes, compared to alts, Bitcoin is considered stable.)

codexon 9y ago
What you say doesn't really disprove my point. Yes you can change to a different algorithm. But the underlying principal is the same. You require participants to spend X time in a problem with no shortcuts. Changing the problem does not allow you to bypass this issue. If you choose a problem that requires less time to calculate, you increase the probability that someone spams the network with fake data. https://en.wikipedia.org/wiki/Proof-of-work_system https://en.wikipedia.org/wiki/Proof-of-work_system You either have a centralized system that can cheaply tell you if something is legitimate, otherwise this is the only way to protect a decentralized system. To my knowledge, there is no altcoin with any significant amount of use that does not use this principal. Please tell me which altcoins do not use this principal.
- Retric 9y ago
  If you do 1 transaction every minute then someone needs a ~51% attack to "win" after 10 minutes because without that you will not have the longer chain. Having a protocol that can do 1 minute blocks is hard, but not nessisarily less safe because it's number of clocks * computing power that provides safety not the actual effort a block takes.
- placeybordeaux 9y ago
  > If you choose a problem that requires less time to calculate, you increase the probability that someone spams the network with fake data. No you just decrease the faith you can put into each confirmation. > You either have a centralized system that can cheaply tell you if something is legitimate, otherwise this is the only way to protect a decentralized system. There are some interesting efforts to create systems that work in complement to the main block chain. One complimentary idea is the lightening network which functions by creating channels that only transact of bitcoins that are currently locked out of the bitcoin system. This eliminates the potential for double spending these bitcoins in a tx with a third party. Once you eliminate the potential for double spending you can do just about whatever you want quickly and off chain. The system is set up to be able to be able to resolve all of the txs that happened off chain when the locked up bitcoins are unlocked. Once many of these channels are established you can start to establish a connection. For instance if I have 12 bitcoins in my own wallet I might keep ~1 BTC locked up to a connection to coinbase. From there they may charge a fraction of what the on chain cost for any tx would be. It'd take a regular on chain fee to establish the connnection, but once it is up the fee and latency should drop dramatically.

virtuexru 9y ago

SHA256 is not going to be broken by Moore's law computational improvements in our lifetimes. If it's going to get broken, it'll be by some breakthrough cracking method. An attack that could so thoroughly vanquish SHA256 to bring it within computationally tractable range has a good chance of clobbering SHA512 too. From Satoshi's post on BitcoinTalk: https://bitcointalk.org/index.php?topic=360.msg3520#msg3520 https://bitcointalk.org/index.php?topic=360.msg3520#msg3520