i have a device A that holds a private key Sk(A) and its respective public key Pk(A).
I’ve also a backend service B that holds a private key Sk(B) and its respective public key Pk(B).
A knows only the address string of B.
I want to create a 2/2 Multisig transaction, where both the signatures of A and B are required.
Is it possibile to send a signedTransaction (by A only) to the backend B (so a conversion of the transaction to a JSON format - like) and make B to append its signature to the transaction and then send it to the blockchain?
I want to achieve this using JavaSDK.