Ethical Hacking - Cryptography

    We use internet in day to day life for communication, transactions, sharing information or data. Data security is critical to secure our online sensitive information such as credit cards details, PINs, bank account details, private messages etc. So, Cryptography is introduced to secure data against interception and compromise during online transmissions.

    The term “Cryptography” has been come from the Greek word kryptos meaning “hidden, secret or mysterious” and gaphia meaning “writing”. Thus, cryptography is “the art of secret writing”.

Cryptography is a technique of encrypting the plain text data into a cipher text. This encrypted data is sent over public or private network towards destination to ensure the confidentially.

Cryptography Process
The plain text (readable format) data is encrypted using encryption tool into a cipher text (unreadable format) and send to a particular destination. On reaching the destination, the cipher text (unreadable format) is decrypted into plain text (readable format).

Types of Cryptography
1. Symmetric Encryption
In symmetric encryption the same key is used for both encryption and decryption. The sender uses a key to encrypt the plain text into cipher text and send to a recipient. The recipient uses the same key (used for encryption) to decrypt the cipher text into plain text. It works faster than asymmetric encryption and is simple to implement. However, the major risk is the encryption key being leaked or compromised. If the encryption key is stolen by any means, then any person possessing that key will be able to encrypt and decrypt data in an unauthorized manner.

2. Asymmetric Encryption
Asymmetric encryption uses separate keys for encryption and decryption. The key used for encrypting the data is referred to as the public key, while the key used for decrypting the data is referred to as the private key. The public key of recipient is available to anyone. The sender uses the public key of recipient to encrypt plain text into cipher text and send it to recipient. The recipient uses private key to decrypt the cipher text into plain text. Although this makes the process a bit more complex and slower than symmetric encryption, it certainly offers better protection against the risk of keys being compromised. Asymmetric encryption is also known as public-key cryptography.