Hal Hodson, technology reporter Bitcoin is the perfect currency
in many ways. The distributed network that governs the creation
and distribution of this digital money means there's no need for
central banks, no centralised control, nothing to come between
you and your cash. But it does have a privacy problem. The lack
of need for a bank or any central authority is derived through
the distributed Bitcoin network, which verifies all transfers
across multiple nodes to ensure that no coin is spent twice.
This means a record is kept of all transactions between
accounts, known as wallets. Although there's nothing that
immediately links these accounts with real people, it's
relatively easy to link purchases and figure out who's spending
what. Researchers at Johns Hopkins University in Baltimore,
Maryland, have come up with a way around this problem. Called
Zerocoin, it's a cryptographic add-on to Bitcoin that allows for
transactions which cannot be linked together. The key is that it
does this without introducing an