Suppose you are designing a TCB for a system that will need

Suppose you are designing a TCB for a system that will need to communicate over the Internet. Describe cryptographic methods you could use to implement a trusted path between systems.

Solution

Here some of the cryptographic methods used to implement a trusted path between systems..

(i) Symmetric cryptography
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It is most traditional form cryptography method. In this method both parties share comon secret password.
This method is very fast. Some of the methods are DES, 3DES and AES. Normally use 56-bit

(ii)
Asymmetric cryptography..
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It uses two keys one for encryption purpose and another for decryption purpose. These keys are not shared
with two parties. Comparive to symmetric xryptography it is bot slower but more powerful and secure.
Examples are PGP and SSL.

(iii)
Hashes
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This method will take some data of aribitary length to generate key. And this key is based on input.
It is easy to encrypt data but bery difficult to decrypt to priginal text. So thats why these algorithms are
very widely used abd powerful.
Examples are MD5 and SHA-1.