Quantum Computing Concerns for Digital Currency

When researching information on the effects quantum computers will have on Bitcoin and other cryptocurrencies I found many different opinions. One thing people seem to agree on though… all technology must continuously evolve or be compromised.

Quantum computers are going to vastly increase the speed of even the fastest machines in the world today. Many people in the Bitcoin and Altcoin communities fear this speed increase will allow the private key of any crypto-transfer to be deciphered from the public key in the time it takes for the transaction to be sent and received. This would potentially allow the transaction to be altered or disrupted. This is not only a cryptocurrency problem. It could potentially cripple many banks and businesses.

To understand the power of quantum computers, you need to have an idea of how quickly this new technology could change things. I have been trying to come up with a way to explain how quantum computers will work so anyone can understand. This is a difficult explanation to give because if it was something that could be done with technology we have today, it would already be built. Quantum computing will be something new.

As you probably know, today’s computers use bytes which are sent with one of two values, a 0 or 1, to pass information. The best simple explanation I found defines a quantum computer as being able to handle multiple 0’s and 1’s in a single byte. Each set of 0’s and 1’s used is called a qubit.

For example, if a quantum computer utilizes 2 qubits, it has 4 possible combinations in a single byte:


0, 0

0, 1

1, 0

1, 1


This would allow twice as many combinations as computers have today, potentially doubling the speed data can be passed. If you add a 3rd qubit, you double it again to 8 combinations, and a 4th qubit doubles it again to 16 times as much information passed at once. As quantum technology emerges and improves, you can imagine how the speed of these computers will explode exponentially. Someone recently claimed to have the technology to incorporate 10 qubits, which would send 1024 times as much information in a single byte as computers can pass today.

So, how secure is the average crypto-currency blockchain transaction today? Could a computer working over a thousand times faster than today’s super-computers break Bitcoin’s security quickly enough to cause problems?

In basic terms, the key to securing most blockchain transactions is the SHA, or Secure Hash Algorithm. Bitcoin, and almost every other cryptocurrency, currently runs on SHA-256 encryption which creates a 64 character string to represent the information within a transaction. If you were able to decipher the SHA-256 string for a Bitcoin transfer quickly enough, you could see the details before it was confirmed. (Note: There is more to breaking a Bitcoin transaction than just decrypting the Public key. I am keeping it simple for this illustration.)

Here is a site you can visit to get an idea how SHA-256 encryption looks. Type whatever you want in the box to see the hash value created.




SHA-256 encryption is recommended by the NSA and is complex enough to remain secure for today’s blockchain transactions. Technically, it is possible for a supercomputer to break it, but not nearly fast enough for a Bitcoin transaction to be deciphered before it is confirmed.

Improved encryption already exists. SHA-512, for example, is a similar algorithm generating 128 characters. Compare the hash value you receive from the SHA-512 generator below to what you received for SHA-256.




SHA-256 and SHA-512 security were developed in 2002 and run using a hash function called SHA2. In 2008 NIST, the National Institute of Standards and Technology, held a competition to find an even more secure possibility, and the SHA3 technology standard was created. SHA3 is rarely used today because SHA2 has still proven itself to be unbreakable for the average data transfer.


Read more about SHA2 & SHA3 here:  https://en.wikipedia.org/wiki/Secure_Hash_Algorithm


This SHA3 technology has already been defined and is available to make Bitcoin and other currencies more quantum computer proof than they are today. A few cryptocurrencies, such as Nexus, have already embraced the more secure SHA3 security, but most others are at possible risk.

Does this mean Bitcoin is doomed by quantum computers as some would have you believe? No… or at least probably not. The jury is still out. Some people say early quantum computers will not be able to break SHA-256 quickly enough. Others say Bitcoin, and most other currencies, will be vulnerable and need to update to stay secure.

However, the undeniable truth is someone, someday will have a computer that runs fast enough with a program complex enough to break the SHA-256 security used today. Will it be when quantum computers come out? Will it be ten years down the line?  We cannot be sure. We do know Bitcoin, and other crypto currencies, have become extremely valuable, and people are working every day to find a new way to steal some for themselves.

So the question for us, the entire crypto community, is… Are we doing something today to prepare or are we going to wait for the day disaster strikes to fix the inevitable problems quantum computers will pose in the future? The answer for each currency may be the difference between the ultimate winners and losers.

If you have found the information here helpful, it is widely encouraged in the crypto world to send a small tip in appreciation.  You won’t find many crypto sites charging fees.  Instead people share ideas, information, and even programs freely in exchange for voluntary donations.  On one of my other sites I received only .002 BTC in the last year, so I am always appreciative of anything people are gracious enough to give.

My Bitcoin Address: 1EPyFDbRtfxMvpAhCyXBH2xwMuJ77Wwb41


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