bls12-381 verify method with G2 curve not working

[parviz-mv]

Hi! I'm trying to verify the created signature with the bls12-381 G2 curve, but I'm encountering the following error:
Error: bad point: equation left != right .

First, I generate a key pair, then create a signature using the private key. After that, I attempt to verify the signature using the public key:

const privateKey = bls12_381.utils.randomPrivateKey();
const publicKey = bls12_381.G2.ProjectivePoint.fromPrivateKey(privateKey).toRawBytes(true);
const message = Buffer.from("Hello world!").toString("hex");
const signature = bls12_381.sign(message, privateKey);
const isSignatureValid = bls12_381.verify(signature, message, publicKey);

Also, in the documentation of @mattrglobal/bbs-signatures, it is stated that the length of the signature must be 112 bytes for the G2 curve. However, I am getting 96 bytes.

Everything works fine when using the G1 curve. However, I suspect that the implementation for G2 is not yet available. Could you please confirm?

[paulmillr]

public key must be in g1 for signatures to be in g2

[parviz-mv]

@paulmillr thank you for response. I mean can I create signature using G2 key as public key? Is not supported at all or just not supported by library?

I am confused by another BLS/BBS implementation which is using G2 public key for signing:

Element	Size Equation
Private Key	F
Public Key	G2
Signature	G1 + 2*F
Proof	5G1 + (4 + no_of_hidden_messages)F

[paulmillr]

G1 is used for public keys, G2 is used for signatures If you need G1 sigs and G2 pubkeys, we don't support it: see #74