Sigma solutions use hash algorithms in the communications between departments while transferring confidential files. A human resource employee informed you that one of the employees' salary statements sent from her end looks tampered with and requested your help. Which of the following tasks would enable you to identify whether the file is tampered with or not, and how will you make the determination?
Check the digest for the file size. If the digest file size is different from that of the original digest, it can be concluded that the file has been tampered with.
Check whether the original plaintext can be generated from the digest. If the original values can be generated and match the original file, the file has not been tampered with.
Check the file digest for alternate values. If the digest's alternate value is the same in the entire digest, the file can be confirmed to be not tampered with.
Check the digest of the file with the original digest. If the values are different, it can be confirmed that the file has been tampered with.