Huawei IP Phone eSpace
7810&7820&7830&7850&7870&7803X
Administrator Guide
2 Single IP Phone Configuration
Issue 01 (2011-12-31)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
83
An IP phone uses HTTPS to perform automatic provision, during which the IP phone
functions as a client.
When a user uses HTTPS to access an IP phone's web page, the IP phone functions as a
server.
Encryption Algorithm
Encrypted transmission occurs when data sender uses the encryption key to encrypt
information and then sends the encrypted information to the recipient. The data recipient uses
the decryption key to decrypt the information and reads the information. Two common
encryption algorithms are described as follows:
Symmetric-key algorithm: The encryption key is trivially related to the decryption key,
in that they may be identical or there is a simple transformation to go between the two
keys.
Asymmetric-key algorithm: This algorithm involves a public key and a private key. If the
public key is used for encryption, only the corresponding private key can be used for
decryption; if the private key is used for encryption, only the corresponding public key
can be used for decryption.
TLS/SSL Communication Principle
The process for TLS/SSL communication is as follows:
1.
The client and the server use the asymmetric encryption algorithm to negotiate a session
key. The sender generates a symmetric session key and uses the public key to encrypt the
session key. Then the sender sends the encrypted information to the recipient.
2.
The recipient uses the private key to decrypt the session key.
3.
The sender uses the session key to encrypt a file and sends the encrypted file to the
recipient.
4.
The recipient uses the session key to decrypt the file into a plain text.
The file transmission is secure because only the private key of the recipient can be used for
decrypting the session key.
Communication Process
After the TLS/SSL connection is set up, data can be transmitted securely.
Figure 2-43
shows
the transmission process.
