Question

May I know how to arrange shared symmetric session key with public key cryptography assume there is no KDC server around.

Thanks

Answer 1

Answer)
Cryptography is the technique of converting the plain text into non-human readable ciphertext. Encryption is the technique of converting plain text to cipher text and decryption is the one of converting the ciphertext back to human readable and meaningful plain text. The process of encryption is that we have to apply cryptographic algorithms so that the message cannot be read or cannot be understood by unauthorized persons. Only authorized persons will be able to decrypt the ciphertext back to plain text.

The public key cryptography has the technique in which the sender and receiver have a public and private key. Here the public key is broad-casted while the private key is private. The message is encrypted with the receiver's public key and the message is decrypted using the private key of the receiver on the receiver's side. Thus there is the reason why the public key cryptography is more secure than the symmetric key cryptography.

How we can arrange a shared symmetric session key with public key cryptography is that, firstly we can generate the symmetric session key which is to be shared with the members using the public key cryptography, and thus the symmetric session key would be decipherable only on the genuine receiver's side as only the receiver with the receiver's private key would be able to decrypt the message. And thus, the symmetric session key can be shared using public key cryptography in a secure manner.