Blockchains were originally designed to go slow. The first chain to really grow to scale was Bitcoin, which is widely known to have a limit of 7 transactions per second (TPS). That is fast enough for some very good use cases. 1/7th of a second is fast enough to be instant for most situations, and is much faster than processing a credit card, or even counting cash. The issue is that it is not 1/7th of a second for your transaction, but rather 2,500 transactions per block, which takes about 10 minutes. A lot can happen in 10 minutes!

Buying expensive things like a house or a car can take days or even weeks to close, so waiting 10 or even 30 minutes for the money to move isn’t a big deal. For smaller purchases, which can happen much faster, there is a threat of double spend – where a user tries to pay with the same coins twice. This can happen if the second transaction occurs before the first transaction is shared to the pending transaction list.

In situations where the coins were paid for something that was instantly transferred (like ready-to-eat food) and can’t be returned, a user can create two transactions which compete in the pending transactions: one to the restaurant and another to a different wallet they also own. Whichever transaction gets added to the main chain first will be the one that is correct, and the other will be forgotten.

As with all valuable transactions there are safeguards put into place to protect against this, but it remains a cat-and-mouse game where, if there is value in cheating a system, somebody will find a way to do it.

In this case speed is a tool for security. Where you can process transactions faster, you can have better security against double spending. This has been one of the biggest hurdles for traditional blockchains to overcome, and the main reason why credit cards and other direct payment methods remain the primary transaction mechanism in place.

With the advent of quantum computing, a hypothetical situation could arise: what if one miner—or a mining pool—suddenly controls over 50% of the network’s hashing power? Would the world even notice?

Naturally, if all newly minted bitcoins began flowing into a single wallet, it would raise immediate suspicion. But a sophisticated attacker could easily obscure this by distributing coins across multiple wallets. If they’re clever enough to corner the market, they’re likely clever enough to conceal their activity.

With a substantial advantage in computing power, this dominant miner could begin altering the algorithm used to build blocks. Rather than selecting pending transactions randomly or based on the highest gas (transaction) fees, they might prioritize transactions involving newly minted coins.

This behavior would effectively devalue older coins. Coins that haven’t moved in years could become harder to spend—not because they’re invalid, but because if miners don’t include those transactions in blocks, the coins effectively remain frozen. Some older coins would still make it through, especially when selected by independent miners or when accompanied by large enough fees. But overall, the value of “new” money would rise compared to “old” money.

If this scenario unfolded, the use of an alternative block selection algorithm would eventually become noticeable. But what could be done about it?

A fork might naturally occur, separating “new money” from “old,” but a traditional fork wouldn’t help much—since the dominant miner could continue operating on both chains. They wouldn’t be breaking any existing rules, and there’d be no effective way to stop them unless the rest of the network’s miners caught up in hashing power.

For now, the 51% attack remains a theoretical risk—one to be watched, but not feared. No one has yet developed the quantum hardware or algorithm necessary to carry out such an attack. And if anyone does, it’s likely to be a nation-state actor with ambitions far beyond cryptocurrency.

We see a world where everyone has access to digital currency, with a secure infrastructure and fast transactions. It shouldn’t take a finance degree to understand the money in your wallet, and paper money should behave just like digital money. We have created Your Coin to give banks a mechanism to rewrite the financial world in a manner where they can still provide valuable guidance and reap the relevant rewards by helping everyone use money that is even greener than the US Dollar.

To mine a block in a traditional blockchain, you need to calculate a hash. But what exactly is a hash, and why are so many of them wasted?

To understand hashes, let’s start with the concept of functions. Take a simple example: a function that adds the inputs, such as two and three add up to five. We can write this as F(2, 3) = 5. If we apply the same function to 2, 3, and 4, the result is 9. If I told you that F(X) = 9, you could try to solve for X. One possible answer would be X = 2, 3, and 4; another would be X = 1 and 8. For simple functions like this, it’s relatively easy to solve them in either direction—using addition forward and subtraction in reverse.

However, functions become more difficult to reverse as they grow more complex. Functions involving prime factorization or squaring inputs, for instance, may be easy to compute in one direction but extremely hard to solve backward. Even powerful computers can struggle to reverse them efficiently.

Hashing algorithms are a type of complex function with a special twist: their outputs are formatted to a fixed size. That means no matter what data you input—whether it’s a single number or a dataset with a million digits—the output hash will always be the same size. Since these algorithms are mathematical at their core, everything can be reduced to numbers: think ASCII codes or binary. In the digital world, it all comes down to bits.

To mine a new block on a blockchain, you start by organizing your inputs. These include metadata such as the block number, the previous block’s hash, your reward address, and any other required details. Then you add a group of validated transactions that need to be permanently recorded. Finally, you include a counter known as a nonce. You feed all of this into the blockchain’s hashing algorithm to generate a single hash representing that block.

The catch? While the hash output is always the same size, only certain hashes are acceptable. In Bitcoin, for instance, there’s a difficulty rating that defines an upper limit for valid hashes—essentially requiring that the hash begin with a specific number of zeros. To find such a hash, miners must try countless combinations of metadata, transaction sets, and nonces.

If a miner does find a hash that meets the criteria, they broadcast it to the network. Other nodes can quickly verify that the block is valid, as it is easy to prove an answer is correct, whereas it is very hard to find a new correct answer. It is kind of like a jigsaw puzzle where every piece is numbered at random: if somebody tells you the right order you can put it together quite quickly, but if you are guessing randomly you may not live long enough to find the solution. If accepted, the community begins mining the next block using the new one as a reference.

But what happens to all the hashes that didn’t make the cut? They’re discarded. The time, effort, and electricity used to generate them are essentially wasted.

As we move toward a more sustainable digital economy, we must look for greener alternatives that don’t depend on burning massive amounts of energy just to validate transactions. The future of digital currency should prioritize efficiency and environmental responsibility.