Application-Layer Security Tools
•Pretty Good Privacy (PGP) , Gnu Privacy Guard (GnuPG)
•used to encrypt and digitally sign files for file transfer and email
•Secure/Multipurpose Internet Mail Extension (S/MIME)
•Used to secure email at the application level
•Supported by email clients such as MS Outlook and Netscape Messenger
•Secure Shell (SSH)
•Provides remote access to a command prompt across a secure, encrypted session
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