Two way communication using asymmetric encryption According to image 1, for two way communication, each person needs to generate a pair of keys. However, according to image 2, only one pair of keys is required for two way communication. Thanks to anyone who can settle my confusion.

Source 1


  If a two-way communication is required between all five workers, then they all need to generate their own matching public and private keys. Once this is done, all users then need to swap public keys so that they can send encrypted documents, files or messages between each other. Each worker will then use their own private key to decrypt information being sent to them.


Source 2


  the other key is known as the private key. Data encrypted with the public key can only be decrypted with the private key, and data encrypted with the private key can only be decrypted with the public key. Public key encryption is also known as asymmetric encryption. It is widely used, especially for TLS/SSL, which makes HTTPS possible.
The first source is being imprecise when they say "need".  What they mean is that this is one way to accomplish it.

The second source doesn't say what you claim it says.

I suggest studying key exchange protocols and learning how SSL works.