-----BEGIN BITCOIN SIGNED MESSAGE-----
Today is 07-03-2018 and i ask u verify me message with username : PonyBoy
-----BEGIN SIGNATURE-----
1NjBULuNMKTC4o41wowZeV11uHi2AS4XC9
INz5jArl0JaTlD923d0z1f8NZBstO1GTdkybRTg0mS27cHCsmtgsT03N87jgMVMxQtKmK8ZY6Imzbb4 gvV/EDHw=
-----END BITCOIN SIGNED MESSAGE-------
Quoted and verified with Electrum 3.1.0
I am seeing a lot of people signing messages with Segwit Address (starting with 3 or b).
There is no standard to verify these addresses.
Electrum is somehow verifying them, but only Electrum, and it's nonstandard.
In future there will a standard for those address, to be verified in any wallet, and not necessarily the same Electrum did. In future those signed messages may not be able to be verified. I think it's better to sign with a legacy address for now.
Nope, once other wallets support bc1 addresses, they will eventually be able to verify those addies.
That's not necessarily the case as there are no standards yet.
There is no standard for signing messages with segwit addresses yet. That's something that is being worked on. Note that messages aren't actually signed with an address. Rather they are signed with a public-private key pair which can correspond to multiple addresses. Your wallet software will calculate the public key for a message and convert that into an address. A wallet could just as easily show you a P2SH-P2WPKH or P2WPKH address instead of a P2PKH address when it is verifying a signed message. What needs to happen is a specification for signing messages with a script which can thus be generalized to signing with an address. Such messages and signatures would actually correspond to addresses and not a public key which your wallet just turns into an address.
Electrum tends to implement their own formats for things and not get them standardized. They have implemented their own segwit private key, public key, seed, and signature format which is specific only to Electrum (the signature format might work with Trezor).
I don't think there is any problem using a bech32 address from Electrum as the forum admins have access to Electrum and will be able to verify your message.
