Tech Talk.....Cryptography or Encryption [Introduction]

Recently, I was working on securing the communication between different components of my product using cryptography or encryption (as it was called in the old world), I explored and learnt various concepts related to cryptography which proved to be very helpful. However, they were scattered around a lot and I had to filter out lots of stuff from here and there. I would like to summarize the learning that I gathered, over a series of small posts here, that would help someone like me in the future save time and effort and keep the learning crisp and fast.

Cryptography is a way to secure communication between two parties from any third party. In the world of computers, there are two different kind of cryptography techniques that are mostly popular : Public key cryptography (also known as Asymmetric cryptography) and Symmetric cryptography.

Public key cryptography:

This cryptography or encryption technique uses a pair of keys for encryption - decryption, one being a private key and another being a public key.Private key is used for decryption of data and public key is used for encryption of data. This mode of encryption is famous in the client - server world where the server generates a pair of keys - a public key and a private key. The private key is retained with the server , while the public key is made available to any client that wants to communicate to the server. The client encrypts its data with the public key before sending it over to the server, when the server gets the data from client, it uses the private key to decrypt the data. If any third party gets hold of the encrypted data, it can't decrypt the data because it won't have the private key with it.

In the next post, I will show how to generate a public-private key pair, how to store it and how to use it.(In java)