A method for performing access control in a memory device, the associated memory device and the controller thereof are provided. The method includes: according to at least one predetermined arrangement pattern, writing a plurality of sets of symbols into a plurality of storage regions of a memory as a plurality of redundant array of independent disks (RAID) groups, respectively; and utilizing a RAID engine circuit in the memory device to perform a plurality of operations related to data protection, such as: determining a series of reading patterns corresponding to the predetermined arrangement pattern; according to a reading pattern of the series of reading patterns, reading a plurality of symbols from each RAID group of the RAID groups; and performing exclusive-OR (XOR) operations on the symbols to convert the symbols into at least one XOR result, for performing data protection.