The Bitcoin Sidechain functionality has been implemented in the Peerplays blockchain but it doesn't take into account, the change of SONs. As per the current implementation of Sidechain, a multisig bitcoin wallet will be created on the bitcoin blockchain to hold the bitcoins that have been deposited into the pBTC accounts of the Peerplays users. Every SON will have a bitcoin transaction signing key for this multisig bitcoin wallet and will be required to sign any withdrawal transaction. When a SONs changes, the transaction signing key of the outgoing SON needs to be removed from the multisig bitcoin wallet and the key of the incoming SON needs to be added. The suggested proposal is to make the Sidechain code available as a plugin and assign the responsibility for running the sidechain code to separate nodes called the Sidechain Operating Nodes (SONs).