The invention discloses an Excel
ciphertext document
recovery method,
computer equipment and a storage medium. The document
recovery method comprises the following steps: constructing a key
rainbow table of an Excel document: constructing the
rainbow table according to an RC4
encryption algorithm adopted by the Excel document; decoding a decryption key of the Excel
ciphertext document: decoding anintermediate key of the Excel document by utilizing a
rainbow table
attack, and taking the intermediate key as the decryption key; decrypting and restoring the corresponding Excel
plaintext document:decrypting and restoring the
plaintext document by utilizing the decrypted decryption key and the Excel document
ciphertext data
storage structure information. According to the method, the
rainbow table for
cracking the secret key only needs to be constructed once, the generated
rainbow table is suitable for secret key decoding of all Excel ciphertext documents, and therefore
recovery of the Excel ciphertext documents is realized. The document
recovery method is irrelevant to the complexity of the document
encryption password, the defect that a complex
password cannot be cracked in an existing document
cracking method is overcome, and the RC4 encrypted Excel document can be effectively recovered.