The three tier  client/server architecture was introduced in the 1990’s to overcome the shortcomings prevalent in the two tier architecture.

Security enthusiasts define the three fundamental aspects of security as people, protocol and security/encryption. Providing all three of these aspects are continually evaluated and adhered to, the less chance there is of an attack. The recent incident whereby confidential social security details were shipped via courier to Government offices, but never received, clearly highlights the people and/or protocol aspects to be at fault.

I'm particularly wary of the end part.. 

Thank you as always EF!

Hi,

Security enthusiasts define the three fundamental aspects of security as people, protocol and security/encryption. Providing all three of these aspects are continually evaluated and adhered to, the less chance there is of an attack. The recent incident whereby confidential social security details were shipped via courier to Government offices, but never received, clearly highlights the people and/or protocol aspects as being at fault.

Please start a new thread next time.

Best wishes, Clive