The LED block cipher is a lightweight cryptographic algorithm designed for compact hardware implementation and efficient software performance. It is based on AES-like design principles and aims to address three key goals: a simple key schedule, resistance to related-key attacks, and a balance between hardware efficiency and software performance. LED uses a 64-bit block size with 64-bit and 128-bit key variants. The cipher state is arranged in a 4x4 grid of nibbles, and the key schedule is designed to be simple, allowing for straightforward security proofs. LED incorporates a PRESENT Sbox and a modified MixColumnsSerial operation for linear diffusion. The cipher consists of multiple rounds of operations including AddConstants, SubCells, ShiftRows, and MixColumnsSerial. Security analysis shows that LED has strong resistance to differential and linear cryptanalysis, with bounds on the number of active Sboxes. LED also demonstrates resistance to slide and integral attacks. In terms of hardware implementation, LED is highly efficient, with a small area and low power consumption. In software, LED is optimized using lookup tables and XOR operations. The paper concludes that LED is a secure and efficient block cipher suitable for low-resource environments such as RFID tags.The LED block cipher is a lightweight cryptographic algorithm designed for compact hardware implementation and efficient software performance. It is based on AES-like design principles and aims to address three key goals: a simple key schedule, resistance to related-key attacks, and a balance between hardware efficiency and software performance. LED uses a 64-bit block size with 64-bit and 128-bit key variants. The cipher state is arranged in a 4x4 grid of nibbles, and the key schedule is designed to be simple, allowing for straightforward security proofs. LED incorporates a PRESENT Sbox and a modified MixColumnsSerial operation for linear diffusion. The cipher consists of multiple rounds of operations including AddConstants, SubCells, ShiftRows, and MixColumnsSerial. Security analysis shows that LED has strong resistance to differential and linear cryptanalysis, with bounds on the number of active Sboxes. LED also demonstrates resistance to slide and integral attacks. In terms of hardware implementation, LED is highly efficient, with a small area and low power consumption. In software, LED is optimized using lookup tables and XOR operations. The paper concludes that LED is a secure and efficient block cipher suitable for low-resource environments such as RFID tags.