1/ Thread on comparing “reasonably private” spends in #Monero and #Bitcoin
, and trying to find a better way to judge scalability/throughput if all spends provide reasonable/good privacy guarantees.
Starting off with transaction sizes, or more accurately, “private spend size”:

Starting off with transaction sizes, or more accurately, “private spend size”:
2/ I dove into Samourai’s Whirlpool for stats on the Bitcoin side, as they are the de facto privacy implementation for Bitcoin ATM.
Normal "reasonably private spend" TX in Bitcoin: 2,363b, 1,475vb
Normal "reasonably private spend" TX in Monero: 1,700b
Normal "reasonably private spend" TX in Bitcoin: 2,363b, 1,475vb
Normal "reasonably private spend" TX in Monero: 1,700b
3/ I got this data by digging a bit for a “normal” tx0->Whirlpool->STOWAWAY spend, as that is generally regarded as the “proper” way to spend Bitcoin privately. Here are the TX links used:
https://blockstream.info/tx/5787a5eb16bb7e5e16651f5f1bdc5afde146c6f7f5b3516e1ab77c5444128fa2?output:5
https://blockstream.info/tx/4e72519d391ce83e0659c9022a00344bedbb253de1747cf290162b3d3ea51479
https://blockstream.info/tx/ce2394b8d4d3b5be4712184b554c8b8ca6772e5baa1123482b9e50ef5bf2e8a2?input:0
https://blockstream.info/tx/5787a5eb16bb7e5e16651f5f1bdc5afde146c6f7f5b3516e1ab77c5444128fa2?output:5
https://blockstream.info/tx/4e72519d391ce83e0659c9022a00344bedbb253de1747cf290162b3d3ea51479
https://blockstream.info/tx/ce2394b8d4d3b5be4712184b554c8b8ca6772e5baa1123482b9e50ef5bf2e8a2?input:0
4/ Note that the above is not necessarily a linked spend, but merely a tx0/mix/STOWAWAY spend from the same mix instance, so is a good estimate.
I also verified those numbers with several others and was told they’re within the expected range.
I also verified those numbers with several others and was told they’re within the expected range.
5/ That means that for “comparable” (these things are hard to compare, naturally) privacy in Bitcoin and Monero, Bitcoin spends take up ~600b *more* per spend than Monero, and are more difficult to accomplish for the end user.
6/ Now on to costs. This is much more subjective as Bitcoin obviously sees far more on-chain activity:
Normal "reasonably private spend" TX in Bitcoin (excluding "doxxic" change): 0.136USD @ 1sat/vb
Normal "reasonably private spend" TX in Monero: 0.0018USD (median as of 07/20)
Normal "reasonably private spend" TX in Bitcoin (excluding "doxxic" change): 0.136USD @ 1sat/vb
Normal "reasonably private spend" TX in Monero: 0.0018USD (median as of 07/20)
7/ That means that at the absolute cheapest, the private spend costs ~100x more than the Monero spend, for similar privacy guarantees.
This will likely change some, especially as USD prices for both fluctuate, but is good to include in the comparison.
This will likely change some, especially as USD prices for both fluctuate, but is good to include in the comparison.
F/ I was absolutely not expecting this conclusion, and am hopeful to hear more input (and even be shown to be wrong) down the line!
I don’t think this type of comparison has been done before, but I think its a valuable comparison to have!
I don’t think this type of comparison has been done before, but I think its a valuable comparison to have!