Various methods such as AES, DES, and RSA are used for data encryption, but there is a common risk of exposure of cryptographic keys. In this paper, we propose a dynamic key exchange system for the independent cryptographic key generation for each session.
AES was used as the encryption algorithm and Diffie-Hellman public key exchange algorithm was used for key exchange. It is implemented on TCP, and the promised cryptographic key is generated before the session configuration phase by exchanging the public key during the 3-way handshaking.
To verify the performance of the implemented system, the key exchange process is practically shown. And we measured the cryptographic key generation time, CPU usage, bandwidth, and transmission rate to compare the performance with the fixed-key and variable-key algorithms. In addition, experimental results on performance measurement according to various AES key lengths are included.