A semiconductor memory device and a memory system are provided. The semiconductor memory device includes a fingerprint read signal generator configured to generate a fingerprint read signal in response to a refresh counting control signal, a memory cell array comprising a plurality of sub memory cell array blocks, a fingerprint output unit configured to receive data output from memory cells connected to one selected among a plurality of word lines and one selected among a plurality of bit lines of one among the plurality of sub memory cell array blocks in response to the fingerprint read signal to generate fingerprint data, and a pseudorandom number generator configured to perform a linear feedback shifting operation in response to an active command to generate sequence data, receive the fingerprint data in response to the fingerprint read signal, and generate the sequence data based on the fingerprint data.