How much users are aware of the encryption depends upon the processing power of their PCs. InvisiMail and WorldSecure add information to the body of the message so you can examine the information about the message 's signature and integrity. All of the products display warning screens if a corrupted or modified message is received. Of the products, only PGP and WorldSecure support digital certificates. Whether this is important to you will depend on the need for sophisticated authentication for legal or other purposes.
Digital certificates are generally unnecessary for the average end user.
Installation of these products was straightforward, while configuration ranged from simple in the case of American Stealth Messenger to quite complicated for PGP and WorldSecure. To roll out these products on large networks requires either a lot of manpower or a software distribution product. Only PGP is available for Unix and Macintosh. The quality of the documentation varies. American Stealth Messenger 's documentation was sparse, shallow and poorly edited.