http://lxqyom6a3p6fdgsy6mpjyhjqjdpzleseck2jojwwzcilmsvduaeo7zyd.onion/2020/06/11/how-to-prove-control-of-a-bitcoin-segwit-address/index.html
And if you cannot sign a message and ask someone else to verify it, it is very difficult to unambiguously prove control of a public address. This is quite unsatisfactory, given that there are so many upsides to using segwit addresses over old legacy addresses (those that begin with “1”); one of the main reasons is that using segwit addresses significantly decreases transaction fees.