Secure wireless communications are needed in today’s world where we cannot find privacy in any devices we see. So Secretive information is needed with the help of cooperative and secure wireless Communications. Information secrecy is linked with cryptographic secrecy is used for secret-key exchange protocol for wireless networks. Cooperative Communications are used to reduce more power consumption and also increase the capacity of wireless networks.

Cooperative Communications:

Cooperative communications have two terminals, in which the terminals can be both used as data sources and relays. The types of cooperative communications are Ampilfy and Forward method, Decode and Forward method. It was first found by Robert Bacal in 1990. In this method, independent paths are created between source and destination.

Amplify and Forward method:

In this method, the noisy version of the signal is received by each terminal which is transmitted by another terminal and improves the signal and releases the cleaner version of it.

Decode and Forward method:

In this method, the source sends the received bits and sends it to the relay and the relay does the decoding and detection and sends those to the destination node.

Coded Cooperation method:

In this method, each part of the code is sent by both the partners using independent fading paths. Each user tries to send incremental redundancy to their partners. The advantage of this method is that is you don’t need additional users.

Secure Communications:

Secure wireless communications are challenging, mostly they apply cryptographic techniques by using a shared secret key in communication nodes. This method is used for preventing third parties to enter and steal our information. One of the famous secure communications was the green hornet used by Winston Churchill to discuss matters with Franklin D. Roosevelt. We are going to see different types of methods to obtain secure communication.


It is a method which the data is rendered and it is made hard to read by a third party. There are two types of encryption techniques which are Substitution Technique and Transposition technique.

Substitution Techniques:

The basic concept of this technique is that the letters in our information are substituted by symbols. Transposition Techniques: It is a technique in which changes the position of letters in the plain text by performing permutations.


The concept of this method is to hide the useful data by adding more useless data’s. This method is used because Steganography comes from a Greek word “Steganos” which means “hidden”. There are apps that are used for this method which are Xiao, Concealment etc. For In world war II , Steganography was used by microdots covered with a cloth called collodion which was relective.

As we saw all the advantages but the disadvantage is that this secure information can be broken by a method called bugging in which we know a microphone is set in the opponents device so we can hear the conversation of them.


So, we have seen the concept and the methods of Cooperative and Secure wireless communications. As I said in the beginning these methods are useful to secure your information and privacy in today’s world.