PPT-Subverting Bitcoin

David Evans and Samee Zahur Mining Why do we need miners Conflicting Blocks Consensus Majority of hashing power has voted for transactions on longest chain It is costly to increase voting power. Cyryptocurrency Project Proposal - Spring 2015. SHA Use in Bitcoin. SHA256 used heavily as bitcoin’s underlying cryptographic hashing function. Two examples (of many) are its use in the Merkle tree hash, as well as the proof of work calculation. Barter. Goods *BECOME* Money. Acceptable. Durable. Portable. Scarce. Divisible. Recognizable. Gold Storage -> Paper Receipts. England, 17. th. Century. Safety for travelers. Charles I’s Royal Mint loan (1640). What is Bitcoin?. Digital currency created in 2009. Peer-to-peer technology with no central authority. No physical bitcoins; seen as property by IRS. Price is volatile . Uses blockchain technology. Anonymous. Brian Green. What is Bitcoin?. Online Transactions Require(d) a Third Party Intermediary. Paypal. , MasterCard, etc.. “Double-Spending Problem”. 2008 - . Bitcoin: A Peer-to-Peer Electronic Cash . Digital Currency. Chaum’s. ideas in the 1980’s. All ideas required a central bank or . single point of trust. Chaum. started a company. DigiCash. in 1990. Bankrupt. in 1998. Lots of other companies you’ve never heard of have attempted digital cash. Field. Purpose. Updated when …. Size (Words). Version. Block version. number. You upgrade. the software and it specifies a new version. 1. hashPrevBlock. 256-bit hash of the previous block header. Non Centralized, unbacked Mathematical Algorithm that is Digitally exchangeable over a peer to peer network. . What is Bitcoin / Crypto Currency ? . In ENGLISH!. Mathematical code that can be exchanged as money between trusted partners. . Bitcoin . Technology is Game . Changer. Bitcoin != bitcoin. . Decentralized != distributed. Censorship Resistant. Permission-less. Public transactions. Immutable . record. Standardize way to talk money. Digital Currency. Chaum’s. ideas in the 1980’s. All ideas required a central bank or . single point of trust. Chaum. started a company. DigiCash. in 1990. Bankrupt. in 1998. Lots of other companies you’ve never heard of have attempted digital cash. Use our guide to find all of the supported exchanges and bitcoin ATMs within Japan quickly and efficiently. Download it now. Visit: https://www.smartbitcoininvestments.com/buy-bitcoin-in-japan/ Use our guide to find all of the supported exchanges and bitcoin ATMs within Hawaii quickly and efficiently. Download it now. Visit: https://www.smartbitcoininvestments.com/buy-bitcoin-in-hawaii/ Use our guide to find all of the supported exchanges and bitcoin ATMs within Florida quickly and efficiently. Download it now. Visit: https://www.smartbitcoininvestments.com/buy-bitcoin-in-florida/ Use our guide to find all of the supported exchanges and bitcoin ATMs within Washington quickly and efficiently. Download it now. Visit: https://www.smartbitcoininvestments.com/buy-bitcoin-in-washington/ play real bitcoin games and earn real bitcoin by play online casino game.