blockchains 101
TRANSCRIPT
Block chain 101http://big-org.com https://telegram.me/bigorg https://twitter.com/big_org https://www.meetup.com/Blockchain-Interest-Group/
What is it ?It is a data structure that makes it possible to maintain a secure,
immutable, decentralised, transaction system.
A bit of history• In 2008 “someone” called Satoshi Nakamoto published a
paper entitled - Bitcoin: A peer to peer electronic cash system
• In it was proposed a way to create decentralised global ledger amongst peers which could record transactions of a digital currency - Bitcoin
• The technology underlying the global ledger is commonly referred to as “Blockchain”
A simple technical understanding of a
Blockchain
A blockchain can be thought of as a data store that is - • Tamper evident • Decentralised • Un censorable • Self healing
Hash Functions
• What is a hash function ?• A hash is a function that can take an input of any size and return
an output of fixed size. • What is a cryptographic hash function ?
• It is a hash function with certain additional security properties: • Collision free – Not feasible to find x and y such that x != y and H(x) ==
H(y)• So you can compare hashes of 2 pieces of data and if they equal then they are
equal• Hiding – Given H(x) it is infeasible to find x
• Used to “hide” your data so only you can open given the key.• Puzzle Friendly – It is very hard to find x such that H(K|X) = y
• Used in mining for PoW • SHA – 256 hash function
Hash Pointer
• Pointer to where some information is stored is a (cryptographic) hash of the information
• Lets us know where something is and verify if it has not been tampered with.
• Fundamental data structure used in a block chain.
(data)
H ( )
Block Chain Data Structures
Tamper Evident Chain Binary (Merkle) Tree
(data) (data) (data)
H ( )Prev: H() Prev: H()
(data) (data) (data) (data)
H() H() H() H()
H() H()
Consensus on the blockchain
• It is the method by which we ensure that everyone can agree to and trust what is added to the blockchain.
• There are multiple forms of consensus - the dominant one that is used in Bitcoin based systems is Proof of Work (PoW)
• The PoW consensus protocol relies on significant computational power and interested parties or “miners” to validate and confirm transactions, using a structured process for adding transactions records to the blockchain.
• In bitcoin “miners” are given a monetary reward for the work that they do.
Smart Contracts
● An executable set of rules encoded on a blockchain● Censor Proof● Independently Verifiable● Programmable
DApps• Applications on Blockchain• Interfaces to smart contracts • Evolving to be indistinguishable from Web Apps
State of Affairs
● Media tired of Bitcoin Obituaries● Blockchain emerges as the dominant jargon● At peak of Gartner Hype Cycle● VC funding at all time high● Transactions are no more the only use case● Experiments galore in every industry● Altcoins multiply● Blockchain 2.0 concepts mature● Smart Contracts● Security gets importance
Blockchain Challenges
• Scalability: In the blockchain, the system requires significant computational power (hence, electricity) to verify and confirm each block of transactions.
• Confidentiality/transparency: All transactions are public, which has its pros and cons in terms of access to transactional information but not necessarily identification of participants to the network.
• Private blockchains: The idea of a private blockchain while good in theory has a major flaw in that immutability would depend on a single entity. In such a case blockchains would provide little value over a clustered database.
Applications of Blockchain in Bio Informatics
• To record the existence of genomic strains• To create a notarised entry of natural genomes and prevent
prior art.• To share drug databases amongst competitors in a legally
safe manner.• For individuals to record their genetic markers for attribution
and compensation in medical research.
Thank You
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