Peter Todd, Bitcoin Core Developer and Applied Cryptography consultant

1. Scalable Asset Transfer with Single-Use-Seals
Peter Todd
June 14th 2018
Blockchain and Crypto Values
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

2. What problem are we trying to solve?
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

3. What problem are we trying to solve?
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

4. Signatures
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

5. Double-Spend
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

6. Physical Single-Use-Seal
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

7. Cryptographic Single-Use-Seal
Gen(p) → l
Close(l, m, s) → wl
Verify(l, wl, m) → bool
(1)
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

8. Single-Use-Seal Guarantee
Secure if m1, w1, m2, w2 where m1 = m2 such that
Verify(l, w1, m1) and Verify(l, w2, m2) return true.
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

9. Sealed Blockchain
Series of blocks Bi = (wi, li, bi) such that
Verify(li, wi+1, H(li|bi)) is true for each block.
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

10. Implementation: Seal Structure
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

11. Implementation: Seal Serialization
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

12. Implementation: Witness Structure
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

13. Implementation: Witness Validation
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

14. Implementation: Chain of Seals
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

15. Scaling: Proof-of-Publication Seal
Seal defined as l = (Bn, p) where Bn is an initial
block and p is a pubkey.
Verify takes wl = (Bn..Bm) and verifies that
CheckSig(p, m, Bi) returns false for all n ≤ i < m,
and true for i = m.
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04

16. Thank you!
Peter Todd 37EC 7D7B 0A21 7CDB 4B4E 007E 7FAB 1142 67E4 FA04