Blockchains bitcoin

Bitcoin’s blockchain ledger prevents double-spending and keeps track of transactions continuously. It is
what makes possible a currency without a central bank.
Blockchains are also the latest example of the unexpected fruitsofcryptography. Mathematical scramblingisused to boil
down an original piece ofinformation into a code, known as a hash. Any attempt to tamperwith any part ofthe blockchain is
apparent immediately—because the new hash will not match the old ones. In this way a science that keeps information se-
cret (vital for encrypting messages and online shopping and banking) is, paradoxically, also a tool for open dealing.......
The politically minded see the block-
chain reaching further than that. When co-
operatives and left-wingers gathered for
this year’s OuiShare Fest in Paris to discuss
ways that grass-roots organisations could
undermine giant repositories of data like
Facebook, the blockchain made it into al-
mosteveryspeech. Libertariansdream ofa
world where more and more state regula-
tions are replaced with private contracts
between individuals—contracts which
blockchain-based programming would
make self-enforcing......The idea of
making trust a matter of coding, rather
than ofdemocratic politics, legitimacy and
accountability, is not necessarily an ap-
pealing or empowering one.
At the same time, a world with record-
keeping mathematically immune to ma-
nipulation would have many benefits.
Evicted Ms Izaguirre would be betteroff; so
would many others in many other set-
tings. If blockchains have a fundamental
paradox, it is this: by offering a way of set-
ting the past and present in cryptographic
stone, they could make the future a very
different place. 7