Encryption is an effective and increasingly practical way to restrict access to confidential information while in storage. The traditional protection method—a password—has inherent weaknesses and, in many cases, is easily guessable. ACLs that define who has access are also effective, but they often have to be used in conjunction with operating systems or
applications. Further, ACLs cannot prevent improper use of information by systems administrators, as the latter can have total control of a computer. Encryption can fill the security gap, and it can also protect data from hackers who, by means of malicious software, can obtain systems administration rights. Encryption also helps to protect data when a computer or a disk falls into the wrong hands. Many email encryption programs can also be applied to stored data. There are also some encryption products that focus on file protection for computers and PDAs.