What is Public-Key Cryptography?

Public-key cryptography entails algorithm-based cryptographic procedures that are used to randomize and encrypt data. Public key cryptography requires two public and private keys which contain information that is used to randomize data. The scrambled data can only be decrypted using the correct key.

If a user has a plaintext message like “Blockchain”, it can be encrypted using a key “146fhsj77bq10l5g” to appear as ciphertext “dz59YAUB9WNcTu0y7ZBEXg==”. The cipher can then be decrypted using the same key to appear in plaintext.

The protocol prevents any unauthorized attempts to access data by using a pair of keys to encrypt and decrypt the information. The network users receive public and private keys from a network’s certification authorities.

Users that want to encrypt data can obtain the recipient’s public key from a public directory. They can use the key to encrypt the message and forward it to the intended recipient. The recipient can use their private key to decrypt the message. The private key can only be accessed by the recipient.

One of the most commonly used cryptographic systems is the Rivest-Shamir-Adleman (RSA) algorithm. It is used to securely send sensitive data over insecure networks. With the RSA algorithm, both the public and private keys can encrypt messages without sacrificing their authenticity and integrity.

There are numerous advantages to using the RSA algorithm as a cryptographic tool, including:

• Excellent data security. It’s impossible to determine the decryption key by only using the cryptographic algorithm and the encryption key;
• It is considered to be one of the most secure protocols. Unlike private key cryptography, users are not required to reveal their private keys. This reduces the risk of the private key being intercepted during transmission and used with malicious intent;
• Users take responsibility for keeping their private keys secure, meaning that the keys can be used as non-repudiable digital signatures. This is not possible in private-key systems where users have to share their secret keys for decryption.

However, there are also some downsides to public-key cryptography and the utility of the RSA algorithm, such as:

• Public-key cryptography is slow compared to private key cryptographic methods. However, public-key cryptographic methods can be used in tandem with secret-key systems, maintaining the security of the transmission while improving its speed;
• Public-key cryptographic tools can be vulnerable to attacks coming from compromised accreditation entities. Criminals use the public key certificate from a vulnerable authority to imitate them;
• If the user loses their private key, the encryption system becomes susceptible to malicious attacks from criminal entities.