3.145Institutions should not maintain Personal Data on the ledger(s) and such Data should be maintained off-chain.
3.146Data retention will need to be factored into the underlying design of the network for Nodes to purge ledger information after certain defined time periods. Where Data retention rules apply to individual Data sets, destruction of keys used to encrypt the on-chain Data should be implemented.
3.147Depending on the Application, Institutions should consider the principle of interoperability when planning the design of the distributed ledger(s). Institutions should establish processes to prune the distributed ledger(s) and remove records older than a specific time period or enable processes that allow Data stored on the ledger to be forgotten (i.e. destruction of keys used to encrypt Data).