Out in the cryptosphere, there's a vast amount of wealth that's seemingly out of reach.

A long-running statistic suggests four million Bitcoin — almost 20% of the total supply — has been lost forever. Much of it was mined when the network was just beginning, with early adopters tearing their hair out after losing their private keys. One Welshman has endured a nine-year battle as he attempts to receive a hard drive containing 7,500 BTC from landfill. 

But this isn't the only treasure trove that's worth exploring. For example, did you know that over 500 Ethereum presale wallets are yet to be recovered… and collectively, they have a value of several billion dollars?

The presale for ETH — which is now the world's second-largest cryptocurrency — took place back in the summer of 2014. At the time, 1 Bitcoin would buy you 2,000 Ether. Fast forward to now, and the exchange rate is much less generous: 1 BTC will only fetch 12 ETH. A whopping 8,893 people participated in this presale and were given tokens in the genesis block — but according to experts, hundreds of wallets remain untouched.

Some of these wallets contain tens of ETH — a figure that's worth tens of thousands of dollars today. Others have more than 10,000 ETH inside, meaning their owners are missing out on a life-changing $20 million.

All of this conjures up big questions: Are these wallets a lost cause? Will the upcoming merge — where Ethereum moves from a Proof-of-Work to a Proof-of-Stake blockchain — mean these funds are just irretrievable? And what's more, who in their right mind would lose access to their crypto after taking part in a presale?

Well, there are a plethora of factors that can lead to the private keys of presale wallets being lost. It could have been a problem with a browser, challenges with foreign language keyboard settings, or poor security practices. Let's not forget that crypto was shiny and new back then — and many early investors were figuring things out as they went along.

So… what should the people who own one of these presale wallets do? Give up, and dream of what could have been? Use this experience as a gripping story at dinner parties — regaling people of how you missed out on millions of dollars? Or fight back, and begin the painstaking process of reclaiming what's rightfully yours? 

How to recover a presale wallet

It can be done. The first step is to head to Etherscan, a blockchain explorer, and check the balance of the address that you're struggling to retrieve. If there's crypto yet to be claimed, there's work to be done — and it's time to take a step back and reflect on what the password requirements would have been for your wallet.

This next bit is a little more challenging. You need to try and remember the passwords that you commonly used at the time. Software called Hashcat can be used to test a plethora of variations — alternating between uppercase and lowercase characters, and changing letters like a and i for special characters like @ and !. With the right GPU card, you'll have the opportunity to perform 200,000 password checks per second.

All of this may seem like a long shot — and there's still a risk that you'll end up empty handed, unable to find the elusive password to your Ether presale wallet. But this doesn't mean that you're out of options. Next, it's time to get the help of professionals who have a track record of cracking the code and reuniting owners with their crypto. 

KeychainX says forgotten presale wallets often have specific parameters — and it has created custom-made software to successfully recover lost crypto.

The project told Cointelegraph: "Lost crypto wallets are a big headache for many crypto owners. KeychainX has helped over 200 people in the last 12 months to recover millions of lost Ether, Bitcoin and Dogecoin."

The proof is in the pudding

One Ethereum enthusiast contacted KeychainX after being part of the Ether presale — amassing 1,000 ETH for just $300. At the time of writing, this crypto sum would be worth a cool $2 million. There was just one problem: the customer believed the wallet was corrupt.

He was pretty sure of the password, but there were two main problems: firstly, he was half French, meaning there might be a problem with the decryption of foreign characters. Second, the password was 99 characters long. (And to top it all off, the password was of a sexual nature, meaning the project's specialists needed to find common phrases in both English and French that could be tested.)

KeychainX managed to figure out how to translate the special characters that had encrypted his wallet — treating them as they were Cyrillic. It was a process that took several weeks — and on top of all that, it took three days to track down the customer and give them the good news. 

The project isn't just working to retrieve long lost crypto, but prevent the investors of tomorrow from ending up in a similar situation. It's received a patent in the U.S. and Japan for a keyless crypto wallet that uses geolocation data and biometrics to store private keys. And what's more, it's planning to launch an automatic crypto recovery site that will enable people to use their surplus GPU power to join a social recovery system. 

Ethereum co-founder Vitalik Buterin recently shared his vision for social recovery at the Blockchain Futurist Conference in Canada — explaining how the world of Web3 could offer a more effective approach for retrieving accounts than Web2 ever could. As an example, users could nominate five recovery contacts — two of them institutions and one of them an employer, as well as their father and a friend. Three of these trusted sources could then come together to confirm that an account should be unlocked.

Losing crypto can be devastating — but projects like KeychainX are working to ensure far, far fewer people experience this in the future.