There is an client-server app written in Java. They communicate to each other somehow. Unfortunately our technician is not reliable (we are going to fire him).

He accepted that application from the company. They are claiming that everything is secure.

I am not a technican person, can you help me to find out if communication between client and server is encrypted?

I have access to the server. The server is Windows Server.

One suggested to use netstat but I don't know how to use it (which parameters to provide)


3 Answers 3


You should use wireshark to inspect the data. If your application uses a standard encryption scheme (like ssl/tls), you should see the whole handsake process.

If all you see is random binary data, it is very hard to know what it is. With an unknown software, you cannot easily distinguish between compressed or encrypted data (both look like random binary garbage), and you will have to use other means to figure it out (hard, expensive).

If you have a contract with the application developers/company, you should ask them if and what kind of encryption they used.


Actually, the program you will want to use is wireshark. You can use wireshark to capture the actual network traffic that the application is generating and inspect it, then determine what type of traffic it is, what data it contains, etc.


Use a packet sniffer such as Wireshark to view the network traffic. You can run the packet sniffer on either the client or the server. If the application is using SSL, Wireshark should be able to tell show you what cipher was chosen by the SSL handshake. However, if the protocol uses its own encryption scheme, you can't really tell how secure the encryption really is — it could be as secure as AES or as flimsy as repeated XOR with a fixed key.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.