<p>Regarding quantum computers:</p>

<p>If a scalable quantum computer were built, the Bitcoin protocol would become insecure. Bitcoin addresses are derived from the public key in an elliptic curve cryptography system. The whole system depends on the owner keeping his/her secret key indeed secret. Quantum computers could solve efficiently not only the factoring problem but also the discrete logarithm problem:</p>

<p><a href="http://en.wikipedia.org/wiki/Discrete_logarithm">http://en.wikipedia.org/wiki/Discrete_logarithm</a></p>

<p>The security Bitcoin derives from elliptic curve cryptography rests on the assumption that discrete logarithm is hard.</p>

CC BY-SA 3.0
2012-11-23T10:49:54.887Z
I'm new to stackexchange and I still have problems to comment answers that are not mine (there doesn't seem to be an option).
halftimepad
CC BY-SA 3.0
2012-11-16T06:39:59.433Z
It's a good answer, but I think it's more of a follow-up comment to an answer, rather than an answer to the question.
ThePiachu
CC BY-SA 3.0
2014-10-29T06:24:09.423Z
No they wouldn't. If a quantum computer would be built that could actually perform the reverse discrete logarithm (which still *very* far off) it would still take incredibly long to actually do it in practice. Over the years it would be improved, but that is way more than enough time to update Bitcoin with a quantum-proof signature algorithm.
Maǳi Koǌo
CC BY-SA 3.0
2014-10-29T06:24:27.803Z
Oh and besides, in most cases, the public key is only published when its coins are spent. Typically you only have the *address* which is the RIPEMD160 hash of the Sha256 hash of the public key. Good luck inverting that to the private key with any quantum algorithm :)
Maǳi Koǌo
CC BY-SA 3.0
2014-10-29T13:32:57.000Z
Related: http://bitcoin.stackexchange.com/questions/13304/can-a-qubit-miner-asic-device-be-created-and-what-would-its-impact-be-on-the-min
Scott
CC BY-SA 3.0
2012-11-15T22:40:55.727Z
2012-11-15T22:40:55.727Z
halftimepad
<p>The first batch of ASICs will probably be based on "structured ASIC" technology, which is where wiring is laid on top of a pre-defined matrix of transistors. Because the wiring layers are the only layers that need to be defined, structured ASICs are much easier to design than the next most complex form of ASICs, in which the placement of transistors is also customized.</p>

<p>Structured ASICs are very efficient compared with FPGAs; however, if the layout and selection of the transistors is also fully customized, you can get another order of magnitude improvement. My guess is that if Bitcoin continues to succeed for another year, one of the existing ASIC vendors will raise money ($5-10M) to design a standard cell ASIC.</p>

<p>If you think about what your iPhone's graphics processor can do for hour after hour -- all powered by a small battery -- you can get a sense of what a full custom ASIC is capable of in terms of power efficiency.</p>

CC BY-SA 3.0
2012-11-16T15:21:55.963Z
2012-11-16T15:21:55.963Z
Ken Simpson
<p>Probably a step before quantum computers could be ASICs designed using either balanced ternary or imaginary quaternary as their computing bases. Both these bases have slight advantages over binary, as was exposed by Knuth. The Soviets even created a ternary computer, too bad their effort wasn't followed up...</p>

CC BY-SA 3.0
2013-12-21T21:45:43.183Z
2013-12-21T21:45:43.183Z
Joe Pineda
<p>Well, the ASICs machines would probably be more and more refined over the years (like processors), they can get bigger and so forth. So that will probably be the progress for a long while.</p>

<p>Asides that, we have the quantum computers that might be the next big leap forward for all fields of computer science, but for now they can only do really small calculations (3x5=15... on 5 atoms, or something like that). However, there is no telling if and when quantum computers might become viable enough to do anything Bitcoin-related with them, or even whether they might be used to destroy Bitcoin's algorithms altogether.</p>

CC BY-SA 3.0
2014-10-29T13:32:02.623Z
Using quantum computers or "qubits" for Bitcoin mining is addressed here: http://bitcoin.stackexchange.com/questions/13304/can-a-qubit-miner-asic-device-be-created-and-what-would-its-impact-be-on-the-min
Scott
CC BY-SA 3.0
2012-11-15T19:22:32.353Z
Quantum computers don't just do 3x5=15, they do the much harder 15=3x5 (that is, start with 15 and use Shor's algorithm to factor it). And according to Wikipedia, earlier this year a quantum computer managed to factor 21.
Meni Rosenfeld
CC BY-SA 3.0
2012-11-16T09:29:54.370Z
Massively parallel ASIC arrays with efficient job allocation are probably the next step.
Gary
CC BY-SA 3.0
2012-11-15T16:19:22.810Z
2012-11-15T16:19:22.810Z
ThePiachu
<p>Considering that mining progressed from CPU, to GPU, to FPGA, and now ASIC mining... have we finally hit the end of the road for technological advancement?</p>

<p>What future optimizations can occur after ASICs are widespread?</p>

<asic><mining-theory><mining-hardware>
What is more effective than ASIC mining?
makerofthings7
# What is more effective than ASIC mining?

(Asked by: username_0 on 2012-11-15)

Considering that mining progressed from CPU, to GPU, to FPGA, and now ASIC mining... have we finally hit the end of the road for technological advancement?

What future optimizations can occur after ASICs are widespread?

**Tags:** asic, mining-theory, mining-hardware


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## 4 answers

### Answer by username_2 on 2012-11-15. Score: 12 | Accepted answer

Well, the ASICs machines would probably be more and more refined over the years (like processors), they can get bigger and so forth. So that will probably be the progress for a long while.

Asides that, we have the quantum computers that might be the next big leap forward for all fields of computer science, but for now they can only do really small calculations (3x5=15... on 5 atoms, or something like that). However, there is no telling if and when quantum computers might become viable enough to do anything Bitcoin-related with them, or even whether they might be used to destroy Bitcoin's algorithms altogether.

> **Comments:**
> **username_7**: Quantum computers don't just do 3x5=15, they do the much harder 15=3x5 (that is, start with 15 and use Shor's algorithm to factor it). And according to Wikipedia, earlier this year a quantum computer managed to factor 21.  
> **username_8**: Massively parallel ASIC arrays with efficient job allocation are probably the next step.  
> **username_4**: Using quantum computers or "qubits" for Bitcoin mining is addressed here: http://bitcoin.stackexchange.com/questions/13304/can-a-qubit-miner-asic-device-be-created-and-what-would-its-impact-be-on-the-min  

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### Answer by username_1 on 2012-11-15. Score: 8

Regarding quantum computers:

If a scalable quantum computer were built, the Bitcoin protocol would become insecure. Bitcoin addresses are derived from the public key in an elliptic curve cryptography system. The whole system depends on the owner keeping his/her secret key indeed secret. Quantum computers could solve efficiently not only the factoring problem but also the discrete logarithm problem:

<http://en.wikipedia.org/wiki/Discrete_logarithm>

The security Bitcoin derives from elliptic curve cryptography rests on the assumption that discrete logarithm is hard.

> **Comments:**
> **username_2**: It's a good answer, but I think it's more of a follow-up comment to an answer, rather than an answer to the question.  
> **username_1**: I'm new to stackexchange and I still have problems to comment answers that are not mine (there doesn't seem to be an option).  
> **username_3**: No they wouldn't. If a quantum computer would be built that could actually perform the reverse discrete logarithm (which still *very* far off) it would still take incredibly long to actually do it in practice. Over the years it would be improved, but that is way more than enough time to update Bitcoin with a quantum-proof signature algorithm.  
> **username_3**: Oh and besides, in most cases, the public key is only published when its coins are spent. Typically you only have the *address* which is the RIPEMD160 hash of the Sha256 hash of the public key. Good luck inverting that to the private key with any quantum algorithm :)  
> **username_4**: Related: http://bitcoin.stackexchange.com/questions/13304/can-a-qubit-miner-asic-device-be-created-and-what-would-its-impact-be-on-the-min  

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### Answer by username_5 on 2012-11-16. Score: 5

The first batch of ASICs will probably be based on "structured ASIC" technology, which is where wiring is laid on top of a pre-defined matrix of transistors. Because the wiring layers are the only layers that need to be defined, structured ASICs are much easier to design than the next most complex form of ASICs, in which the placement of transistors is also customized.

Structured ASICs are very efficient compared with FPGAs; however, if the layout and selection of the transistors is also fully customized, you can get another order of magnitude improvement. My guess is that if Bitcoin continues to succeed for another year, one of the existing ASIC vendors will raise money ($5-10M) to design a standard cell ASIC.

If you think about what your iPhone's graphics processor can do for hour after hour -- all powered by a small battery -- you can get a sense of what a full custom ASIC is capable of in terms of power efficiency.


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### Answer by username_6 on 2013-12-21. Score: 0

Probably a step before quantum computers could be ASICs designed using either balanced ternary or imaginary quaternary as their computing bases. Both these bases have slight advantages over binary, as was exposed by Knuth. The Soviets even created a ternary computer, too bad their effort wasn't followed up...


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