A memory chip comprises a first memory controller, a first data storage zone, a security unit and an address configuration unit. The first data storage zone is coupled to the first memory controller, and represented by a first physical address range. The security unit is coupled to the first memory controller. The address configuration unit is coupled to the first memory controller. The memory chip is configured to be coupled between a host controller and another memory chip. The another memory chip comprises a second data storage zone represented by a second physical address range. The address configuration unit records one or more relationships of a logical address range corresponding to the first physical address range and the second physical address range. The security unit is configured to encrypt and decrypt data in the first data storage zone and the second data storage zone.