createmultisig nrequired ["key",...]

Creates a multi-signature address with n signature of m keys required.
It returns a json object with the address and redeemScript.

1. nrequired (numeric, required) The number of required signatures out of the n keys or addresses.
2. "keys" (string, required) A json array of keys which are bitcoin addresses or hex-encoded public keys
"key" (string) bitcoin address or hex-encoded public key

"address":"multisigaddress", (string) The value of the new multisig address.
"redeemScript":"script" (string) The string value of the hex-encoded redemption script.


Create a multisig address from 2 addresses
> bitcoin-cli createmultisig 2 "[\\"16sSauSf5pF2UkUwvKGq4qjNRzBZYqgEL5\\",\\"171sgjn4YtPu27adkKGrdDwzRTxnRkBfKV\\"]"

As a json rpc call
> curl --user myusername --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "createmultisig", "params": [2, "[\\"16sSauSf5pF2UkUwvKGq4qjNRzBZYqgEL5\\",\\"171sgjn4YtPu27adkKGrdDwzRTxnRkBfKV\\"]"] }' -H 'content-type: text/plain;'
Don't trust. Verify. Docs extracted from src/rpcmisc.cpp#L233-L260.