In a distributed network hosting a shared pool of configurable computing resources there is provided one or more system instances of a blockchain. Each system instance comprises a virtual machine and a set of containers. The containers are members of the blockchain in that the blockchain's public ledger records encrypted copies of at least selected directories of each container. Each container that is in the set can thus verify whether any other container also belongs to the same set with reference to the public ledger, since the transactions recorded on the public ledger are encrypted copies of the set's containers. The use of a blockchain thus allows a system boundary to be defined around a set of containers by the initial specification of the blockchain. The system boundary can be defined to ensure that the set of containers comply with legal requirements, such as a geographic restriction.