subject: Guidelines For Designing Secure Encryption And Decryption Of Files [print this page] Follow these guidelines when designing secure encryption and decryption of files:
Determine who should be allowed to use EFS, and train these users.Partition the use of EFS. It is not necessary to allow all users to encrypt files. You
can enable and disable EFS in a GPO and link the GPO to any container where you need to either enable or disable the use of EFS.
If EPS will be used, harden it. This can be done by:Ensuring the encryption of temporary folders. Applications can write files to temporary folders. If these folders are not marked by encryption, clear-text copies of your sensitive data might reside in them.a Setting the page file to delete at shut down. The page file can also contain clear-text copies of encrypted documents. Should an attacker be able to obtain physical access to the computer, the page file is protected while the system is running, but when the system is shut down, the attacker might be able to gain access.Use file recovery or key recovery where large numbers of users must be allowed to encrypt files.Use key recovery in high-security situations.If file recovery is used, design a process for file recovery. Require backup of free A+ exam questions encryption keys, and train users how to do it.If file recovery using a PKI will be used:Design a process for file recovery.Create file recovery agents for special accounts. These accounts should not be accounts that are used for user or administrator chores. They can be assigned to and used by authorized file recovery personnel when the need arises.Disable and protect file recovery agent accounts until they are needed.Export file recovery keys, and consider removing the file recovery private key from the network.Provide a separate file recovery station, and import file recovery keys only when necessary to recover files.Back up all file recovery agent keys, and store them in a safe place.If key recovery using a PKI will be used:Enforce role separation.Design the key archival and key recovery process. (See Chapter 2 for addi-tional information on key archival.)Use unique accounts for key recovery agents. Key recovery agents should not be CA administrators or Certificate Managers.Use special accounts for key MCITP certification recovery agents.by: Shirley Green
