[ZIP 227] Attack against Spendability due to ρ potentially not being unique in an issuance action
There are several related issues concerning ρ values for issued notes in ZIP 227 @ 2e8876c. ZIP 227 T.5a.i.4 rho says: Nullifier encoded as 32-byte representation of a point on the Pallas curve. However ρ is not the nullifier of the note *being issued*, and it's not sufficiently clear that there is an extra nullifier here that is *not* associated with a note. If this were an output note of an Orchard[ZSA] Action, its ρ value would be taken from $\mathsf{nf^{old}}$ of the Orchard note spent by the Action.
Radar summary of the original source
Proposal activity—not proof of implementation.
Radar reports the lifecycle label used by the original proposal source. It does not independently infer merge status, implementation, or delivered work.
- Status
- Proposal updated
- Source
- Zcash Improvement Proposals
- Source activity
- Confidence
- Source-linked record
ZIPs
Zcash Improvement Proposals
Radar summary of the original source
Related activity
- Original source
[ZIP 312] Specify key generation, change randomizer handling
Changes to randomizer handling after I realized that it couldn't possibly be generated using the message as an input. It does simplify things too. Some additional fixes (using "Re-Randomized FROST" consistently; updating Owners) fixes #1051 Referenced issue #1051: [ZIP 312] Complete the specification for FROST key generation. This needs to be compatible with quantum resilience.
- Original source
NU7: ZIP 218 rounding lowers the supply cap that ZIP 237 claims to keep
Found by @str4d. ZIP 218 sets the post-NU7 subsidy to floor(MaxBlockSubsidy / (2·3·2^Halving)), so three 25-second blocks pay up to 2 zatoshi less than one 75-second block. ZIP 218 states the resulting shortfall from MAX_MONEY: 0.6720 + (H_3 − A)/10^8 ZEC, of which 0.1848 ZEC predates NU7. ZIP 237 reissues only the NSM Value Balance: pre-NU6 unclaimed value plus removed funds. The rounding loss never enters it, so Mainnet issuance converges to MAX_MONEY minus 67,200,000 + (4,406,400 − A) zatoshi, where A is the NU7 activation height.
- Original source
More NU7 ZIP fixes
Proposal 1403 is tracked from its source repository.