Orfeas Stefanos Thyfronitis Litos
Financial Cryptography 2017
Buyer - Dave
Vendor - Carol
Bob wants to buy sneakers from Alice
But who sends first?
Can't just use escrow: How to trust escrow?
You risk 60m฿ in exchange for being part of the network.
Alice trusts Bob with 5m฿. Both Alice & Bob can spend.
Trust Is Risk graph
Alice trusts Bob will not steal 5m฿ from her.
is the maximum loss Alice can suffer if:
We call this a Transitive Game.
Treat Direct Trusts as graph capacities.
Risk exposure of Alice to Vendor before
Risk exposure of Alice to Vendor after
Collusion = Corrupted Set ∪ Sybil Set
Corrupted Set: Originally trustworthy players, now compromised by Eve. Honest players may directly trust them.
Sybil Set: Players fabricated by Eve. No honest players directly trust them.
MaxFlow cannot be increased by adding nodes without incoming direct trusts.
It's pointless for an attacker to create multiple accounts!
45DC 00AE FDDF 5D5C B988 EC86 2DA4 50F3 AFB0 46C7 <firstname.lastname@example.org> FB61 4CCD 94E1 9201 D144 8D5A 9481 00FD BA28 707E <email@example.com>