Sidechain operating node has access to user accounts mapping list, containing user addresses on supported sidechains. Key value in this mapping is user’s Peerplays account. E.g. [PeerplaysAccount, BitcoinAccount, EthereumAccount, …]. All sidechain accounts should be created by user (e.g. user can enter them during registration as a Peerplays user). Account creation on target sidechain should not be handled by Peerplays, because of increased risk of handling their private keys. This list should be updateable by user.