There are vulnerabilities in multisig protocol if the parties do not
trust each other, and while there is a patch for it, it has not been
throroughly reviewed yet, so it is felt safer to disable multisig by
default for now.
If all parties in a multisig setup trust each other, then it is safe
to enable multisig.
When forced to deal with an untrusted node, a wallet will quantize
its current height to disguise the real height to the adversary, to
try and minimize the daemon's ability to distinguish returning
wallets.
Daemons will thus return more blocks than the wallet needs, starting
from earlier in the chain. These extra blocks will be disregarded
by the wallet, which had already scanned them.
However, for the purposes of reorg size detection, the wallet assumes
all blocks the daemon sends are different, which is only correct if
the wallet hasn't been coy, which is only the case for trusted
daemons (which you should use). This causes an issue when the size
of this "fake reorg" is above the sanity check threshold at which
the wallet refuses a reorg.
To fix this, the reorg size check is moved later on, when the reorg
is about to actually happen, after the wallet has checked which
blocks are actually different from the ones it expects.
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
