Episode 7: Fingerprints
Comparing lists and detecting errors

Whenever our friends at The Blockchain Bar suspect a mistake, they have to compare all entries on the last page with all guests individually. That’s very cumbersome.
Bob is annoyed: “It takes too long to compare every item on the page. There must be a better way.”
Alice has an idea: “Let’s calculate ‘fingerprints’ of our data. Everyone adds up the number of letters in each name on their list. If the sums are identical, the data is probably also identical. So we only have to compare line by line, if there is a mismatch of sums.”
Blockchains do something very similar: They calculate fingerprints of transaction blocks. These fingerprints are called hash values. This makes it easy to compare blocks and identify mistakes or unwanted changes.
But what to do if there are different fingerprints? How to agree on one version? Find out in the next episode…
Or maybe you first want to learn some more about hashing on TheBlockchainBar.com.

The story of Blockruption’s Blockchain Bar began in June 2018, when Martin Breitsprecher and Collin Müller sat in a restaurant in the port of Hamburg. For a long time, they had been trying several approaches of explaining the blockchain to non-nerds. While joking around, they discovered that almost any blockchain concept can be explained with a hypothetical bar that is run by the guests themselves in a beer-to-beer … uh … peer-to-peer fashion.

