CSNP Chicago March 2020

1. Hashing out the
Bitcoin Blockchain
Erin Bailey - BRD

2. Bitcoin Blockchain
● Public ledger of transactions on the Bitcoin network
● Blocks contains a list of transactions
● Each block is uniquely identified by a hash, SHA 256
● Each block contains the hash of the previous block

3. https://www.reso.org/what-is-the-blockchain/

4. Hashing - SHA 256
● Takes in arbitrary-length data, outputs a fixed-length result
○ 000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f
● A single change in the input data results in a completely
different hash
● Virtually impossible to produce a specific
hash
● Virtually impossible to recreate the same hash
with 2 different inputs

5. Guessing Game
● 2256
guesses
● 1 in 115 quattuorvigintillion chance of finding it
○ 115,792,089,237,316,195,423,570,985,008,687,907,853,269,984,665,640,564,039,457,584,007,913,129,639,936
● Exponentially bigger than the number atoms in the perceivable
universe
ba7816bf8f01cf
ea414140de5da
e2223b00361a3
96177a9cb410f
f61f20015ad
1 in 4 billion
chance of
success
4 billion hashes
per second
4 billion
computers
2 billion
Earths
4 billion
galaxies
500 billion
years
3Blue1Brown - https://www.youtube.com/watch?v=S9JGmA5_unY

6. Why does this increase security of
the blockchain?
● Maintains integrity of the transaction, preventing hackers from
fudging the numbers
d66c66a96157220af2fe47c6d564d0d2a61d9d
441a2e52a92bc78b15876053c8
e5d1aefa716e27a97d4f0efbe3ca9f09250bbffcb530
a36a1fa6d8880da96d11

7. Peer to Peer
● All the computers that participate
are equal nodes
● Each node contains the complete
history of the public ledger
● Decentralized, no central authority,
no single point of failure

8. Decentralization
Decentralized - all sensitive
information is spread out and stored
by each end-user
Centralized - all sensitive information
is stored in a single central location,
with central authority

9. Self Sustaining
1. Independent verification of each
transaction, by every node
2. Independent aggregation of those
transactions into new blocks
3. Independent verification of the new
blocks by every node
4. Independent selection, by every
node through “Proof-of-work”
Mastering Bitcoin - Andreas M. Antonopoulos page 181

10. Thank you!
Questions?