Implements view tags as proposed by @UkoeHB in MRL issue
https://github.com/monero-project/research-lab/issues/73
At tx construction, the sender adds a 1-byte view tag to each
output. The view tag is derived from the sender-receiver
shared secret. When scanning for outputs, the receiver can
check the view tag for a match, in order to reduce scanning
time. When the view tag does not match, the wallet avoids the
more expensive EC operations when deriving the output public
key using the shared secret.
bd27deb Bulletproofs+ (SarangNoether)
b7713cc Precompute initial transcript hash (SarangNoether)
b535d66 Updates from security audit (SarangNoether)
a0d80b1 plug bulletproofs plus into consensus (moneromooo-monero)
75bd004 ringct: a few minor optimizations from review (moneromooo-monero)
a345060 ringct: port some of vtnerd's review changes from BP+ to BP (moneromooo-monero)
4c94cfe store outPk/8 in the tx for speed (moneromooo-monero)
5acdd0e bulletproofs+: some minor cleanup from vtnerd's review (moneromooo-monero)
It avoids dividing by 8 when deserializing a tx, which is a slow
operation, and multiplies by 8 when verifying and extracing the
amount, which is much faster as well as less frequent
- combined with patching integer truncation (#7798), this gets the algorithm marginally closer to mirroring empirically observed output ages
- 50 was originally chosen assuming integer truncation would remain in the client for that client release version. But patching integer truncation causes the client to select more outputs in the 10-100 block range, and therefore the benefit of choosing a larger recent spend window of 50 has less merit
- 15 seems well-suited to cover the somewhat sizable observable gap in the early window of blocks
RefreshOptimizeCoinbase was an optimization to speed up scanning of coinbase transactions before RingCT (tx version 2) where they split miner reward into multiple denominations, all to the same wallet.
When RingCT was introduced, all coinbase transactions became 1 output only, so this optimization does nothing now.
With p2pool, this optimization will skip scanning p2pool payouts because they use more than 1 output in coinbase transaction.
Fix it by applying this optimization only to pre-RingCT transactions (version < 2).
- matches the paper by Miller et al to apply the gamma from chain tip, rather than after unlock time
- if the gamma produces an output more recent than the unlock time, the algo packs that output into one of the first 50 spendable blocks, respecting the block density factor
