T1 T in: (T1,1); (T2,3) wit: sig 1 ; sig 2 out: 1 BTC: fun(x) . - PowerPoint PPT Presentation

T1 T in: (T1,1); (T2,3) wit: sig 1 ; sig 2 out: 1 BTC: fun(x) . e1 2 BTC: fun(y) . e2 absLock: after 2018.12.17 T2 relLock: 2 days after T1

● ● ● Block n-2 Block n-1 Block n Transactions: T1 Transactions: Transactions: T2 ... ... T ...

● ● ● Block n-2 Block n-1 Block n Transactions: T1 Transactions: Transactions: T2 ... ... T ...

● ● ● Block n-2 Block n-1 Block n H(Block n-3 ) H(Block n-2 ) H(Block n-1 ) Transactions: Transactions: Transactions: T1 ... ... T2 T ...

● ● Block n-2 Block n-1 Block n

● ● ● Block n Block n-2 Block n-1 Block n-1

● ● Block n Block n-2 Block n-1 Block n-1 Block n+1

● ● Block n Block n-2 Block n-1 Block n-1 Block n+1

● ● Block n Block n-2 Block n-1 Block n-1 Block n+1

● ● Block n Block n+1 Block n-2 Block n-1 Block n-1 Block n+1

● ● Block n+2 Block n Block n+1 Block n-2 Block n-1 Block n-1 Block n+1

● ● Block n+2 Block n Block n+1 Block n-2 Block n-1 Block n-1 Block n+1

● ● Block n Block n-2 Block n-1 Block n-1 Block n+1

● H ( H (block n-1 ) || {T i } || Nonce ) < Target Block n-2 Block n-1 Block n H(Block n-3 ) H(Block n-2 ) H(Block n-1 ) None Nonce Nonce Transactions: Transactions: Transactions: T1 ... ... T2 T ...

● H ( H (block n-1 ) || {T i } || Nonce ) < Target Block n-2 Block n-1 Block n H(Block n-3 ) H(Block n-2 ) H(Block n-1 ) None Nonce Nonce Transactions: Transactions: Transactions: T1 ... ... T2 T ...

● H ( H (block n-1 ) || {T i } || Nonce) < Target Nonce ● ●

Block n Block n-1 Block n-1 Block n+1 Block n+1 ● ●

● ● ● Block n-1 H(Block n-2 ) Nonce Transactions: T Coinbase ...

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Hardware Introduction Hash rate (h/s) 10 5 -10 8 CPU 2009 10 6 -10 9 ● GPU late 2010 10 8 -10 10 FPGA Mid 2011 10 10 -10 13 ASIC Early 2013 ●

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f < 1 γ > λβ λ > 1 λ 2 - fλ + 1 ≥ 0 S S e -Ω(λ^3 k)

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