ZyXEL 35 Guia Do Utilizador

 

 

All contents copyright (c) 2006 ZyXEL Communications Corporation.   

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If the original message is changed in any way, it will not produce the same message digest when the 

hash function is applied. Bob's software then encrypts the message digest with his private key, 

producing a digital signature of the message. He transmits the message and digital signature to Alice. 

Alice uses Bob's public key to decrypt the digital signature, revealing the message digest. Since only 

Bob's public key can decrypt the digital signature, she is able to verify that Bob was the sender of the 

message. This verification process also tells Alice's software which hash function was used to create 

the message digest of Bob's original message. To verify the message content, Alice's software applies 

the hash function to the message she received from Bob. The message digests should be identical. If 

they are, Alice knows the message has not been changed and she is assured of its integrity. (If Bob had 

wanted to ensure the confidentiality of his message, he could have encrypted it with Alice's public key 

before applying the hash function to the message.) 

The best thing about all these encryption, decryption, verifying and authenticating processes is that 

special software does them all transparently, so that Bob and Alice receive the assurances they need 

without having actually to engage in computations themselves. 

 

 

 

No, ZyXEL doesn't maintain CA service for customers, customers need to find CA server (trusted 3rd 

party) in order to use PKI functionality on ZyWALL.