Patent attributes
A method of preventing unauthorized access to electronic mail attachment is disclosed herein. A message management system receives one or more files designated as sensitive files. The message management system generates one or more hash values by applying a hash function to each of the one or more images corresponding to the file. The message management system stores the one or more hash values in a database. The message management system receives an outgoing electronic message that includes an attached file. The message management system generates one or more attachment hash values for the attached file by applying the hash function to the attached file. The message management system compares the one or more attachment hash values to the database. The message management system determines that at least one attachment hash value matches at least one hash value. The message management system blocks the outgoing electronic message.