[Retracted] Blockchain-Based Information Supervision Model for Rice Supply Chains

Algorithm 2

Process of AES decryption.

	Input: plaintext, key
	Output: ciphertext
	/∗ First, the algorithm expands the input key and stores it in W ∗/
	state = ciphertext
	AddRoundKey(state,w) // Bitwise XOR between the extended key in W and the matrix column
	for(r = Nr; i >= 0; i--) {
	InvShiftRows(state) // Rotate each row of the matrix to the right
	InvSubBytes(state) // Find the inverse S-box and output four new bytes to form word
	AddRoundKey(state,w) // In this round of decryption, XOR each column with the extended key
	if(r ! = Nr) {
	InvMixColumns(state) //Inverse column transformation of matrix
	}
	}
	plaintext = state