Wow. Another remarkably dishonest article from the authors of Bitcoin Unlimited. (
Archive link)
because only some coins can
Making your transactions non-malleable is a thing you always opt-into because some forms of mallability are an intentional and useful feature. With a segwit using wallet you get non-malleability by default, you can choose to not have it by using things like sighash flags. Obviously if you don't use a segwit wallet you don't get the segwit benefit. There is no fungiblity interaction here-- any coin can be sent to a segwit wallet and any coins in a segwit wallet can be sent to any other wallet, so that claim is simply untrue.
SegWit absolutely fails to solve anything related to quadratic hashing.
Again, a complete untruth. Segwit makes transaction hashing strictly linear in the size of the transaction. There is no quadratic component at all, and the hashing CPU time for all transactions with multiple inputs is significantly reduced. Because segwit is backward compatible it doesn't change older transactions (and couldn't, without risking confiscating funds) but that is okay because segwit doesn't increase the capacity for older transactions.
It adds a new attack vector,
Dishonest miners being able to make malicious blocks that bloat the system isn't a new attack, but segwit makes the attack better by reducing the much more serious UTXO
bloat attack vector.
I think this point is especially dishonest coming from a BU developer, given that their whole security model is based on a strong assumption that the aggregate behavior of miners is honest. It's like a guy who sells houses without doorlocks on the basis that people are honest complaining that someone was lowering their security replacing their deadbolt with a combination fingerprint scanner + key lock where the key was somewhat easier to copy.
LN strongly incentivize centralization
The description given there actually argues the opposite. The funds in channels are required based on the number of channels. Lightning designs today are setup to only build channels as a product of payments you're already making. Using lightning in a "hub like" way requires extra transactions that you never would have made normally. The big advance of lightning over the prior payment channels proposals is specifically that it doesn't need hubs.
Recently BU's "chief scientist" was making exactly the opposite argument based on the same facts: He argued that lightning did not improve scalablity because there would need to be as many channels as users and so when users went up the channel count would go up.
full blocks equals stealing
This isn't true-- blocks are _always_ effectively full and any system where they aren't is either irrelevant or subject to censorship.
Bitcoin's incentives depend on full blocks, as well.. Lightning works fine in the presence of full blocks, and moreover lightning is largely orthogonal to segwit.
Schnorr cannot deliver any extra capacity
This is simply untrue. Our construction for schnorr aggregation on top of segwit yields over 24% additional capacity in the limit with two outputs and infinitely many inputs, this number is nearly achieved with realistic numbers of inputs like 10 (which achieves a 24.6% capacity increase).
So we have each and every point raised in this blog post are untrue, many absurdly so.
Finally, the untrue claims in this blog post are being plastered all over rBTC
but due to actions by that subreddit's moderators I am unable to post a counterargument-- not just on rbtc-- but anywhere on Reddit. Yet they happily scream about far less limiting actions a censorship.
