Man spends 10 years persuading Newport council to let him dig through landfill site for £130m of buried bitcoins.

The 21st century equivalent of the 1700s phrase 'like looking for a needle in a haystack'

"The real treasure was the interviews we sold along the way"

Could be worse. Could be pig manure.

The bitcoin isn't stored on the harddrive, it's on the bitcoin blockchain, but he stored the key needed to access it on only that one harddrive. Without that no-one can access it.

Bitcoin are associated against addresses which are held in wallets. To transfer coins away from an address (i.e. to spend them or to sell them) you need to create a transaction on the blockchain - as part of doing this you need to “sign” the transaction with a private key associated with the address which holds the bitcoins.

In this case the guy doesn’t have an extra copy of his private key so cannot transfer the coins - he still “owns” them but cannot transact them. It’s like having gold bars locked in a safe but you can’t remember the combination - except the combination is so huge that the chances of guessing it are effectively zero.

Most people who hold more than a trivial amount of bitcoin will have backups of their private key or use mnemonics to remember it but in the early days when 8,000 bitcoins were worth pennies there was no real incentive or knowledge that it was a good idea to keep backups of the key.

The bitcoin are noted in the blockchain belonging to X. The thing that identifies you as X is saved on the drive.

And yes, that is a cautionary tale about making proper backups.

Basically you have a bitcoin account. That account has a username and a password. You can share the username to have people send money to your account. However you can only send money yourself if you know the password to the account. He had his only copy of the password on the hard drive. So if you make two copies of one, you just have two copies of the password to the same account.

What's so special about it is that it's not centralised. With maths you can generate a declaration using your password to attach to your username saying you are sending money and that everyone should update their records. These cannot be faked without a password.

A lot of cryptography and maths goes into it. And the passwords are long strings of random letters and numbers that you cannot choose, same with the username.

It has though, quite tremendously in the last 10 years.

It actually has, tremendously.