Shift registers are cipher components used for generating pseudo random sequences in the field of secret communication, comprising linear feedback shift registers LFSRs, non-linear feedback shift registers NLFSRs, and so on, wherein the maximum period T of the shift register is not greater than 2n. The feedback mode of an n-level non-linear cyclic shift register NRR refers to the following formula, in the formula, i>=0, n>=2, word length m is determined by the number of bits of a platform; <<<j represents ring shift left with j bits; a symbol referring to the description represents modular addition; c is an odd number within the range from 1 to 2<m>-1; initial values a<0>-a<n-1>of n inputted words are unlimited, and each word is an arbitrary m-digit number. When the word length is m bits, the period of the n-level non-linear cyclic shift register NRR is greater than (2<m>)<n>, i.e., the security of the n-level non-linear cyclic shift register NRR is better than the security of a traditional (non-)linear feedback shift register (N)LFSR, and the efficiency of the n-level non-linear cyclic shift register NRR is also better than the efficiency of a common (non-)linear feedback shift register (N)LFSR. The lightweight stream cipher LSNRR is designed through four non-linear cyclic shift registers NRRs, wherein the first NRR is used for secret key schedule, and modular addition is performed for outputs of the other three NRRs to generate a secret key stream of the LSNRR. The efficiency of the LSNRR is better than the efficiency of a common symmetric cipher, thus the LSNRR is suitable for the a resource-constrained environment and a resource-unconstrained environment, and is mainly used for data encryption and decryption.