Rsa Cryptography

Rsa Cryptography

RSA is a widely-used method for secure data transmission. It is a public-key encryption system that uses two large prime numbers to create a unique encryption key. The key can be used to encrypt and decrypt messages, ensuring that only the intended recipient can read the message. RSA is commonly used in electronic commerce, email, and other forms of secure communication, and is considered to be one of the most secure forms of encryption currently available. It was first publicly described by Ron Rivest, Adi Shamir and Leonard Adleman in 1977.

CRYPTOGRAPHY

Cryptography from the word Cryptic; means mysterious.

Cryptography simply means the art and science of how you take something sensible and meaningful and make it into something hard to understand. WHY? To make the truth harder to find.

Cryptography is the practice of securing information through the use of mathematical algorithms, known as ciphers, to encrypt and decrypt data. The purpose of cryptography is to protect sensitive information from unauthorized access, tampering, or disclosure by using techniques that make the information unintelligible to anyone without the proper decryption key. It is used to protect a wide range of sensitive information, including financial transactions, personal communications, and government and military communications. The use of cryptography helps to maintain the privacy and security of sensitive information and ensures that it can only be accessed by authorized parties.

HOW DOES RSA WORKS?

RSA is a way to keep secret messages secret by using special codes. Imagine you have a secret message and you want to send it to your friend, but you don't want anyone else to read it. RSA helps you do that by creating a special code using two secret numbers that only you and your friend know.

  1. First, you and your friend pick two very big secret numbers that no one else knows.

  2. Then you multiply those two big secret numbers together to make an even bigger secret number.

  3. Next, you and your friend each have a special code, one is called the "lock" just like the padlock and the other is called the "key".

  4. The "lock" code is used to scramble the secret message so that no one else can read it.

  5. The "key" code is used to unscramble the secret message so that your friend can read it.

  6. You can share your "lock" code with anyone, but you must keep your "key" code a secret so that only you and your friend can read the secret message.

  7. When your friend receives the secret message, he uses his "key" code to unscramble it and read it.

    So RSA is like a secret code that you and your friend use to talk to each other and keep your secret messages secret from others.

By now, you should have understood how RSA works. Now the following are the steps in generating the encryption key(lock key) and the decryption key(key)

  1. Select two large prime numbers typically referred to as p and q.

  2. Calculate the product of the two prime numbers(n), which is referred to as n = p * q.

  3. Calculate the φ(n) which is called the totient of n, which is defined as (p-1)(q-1).

  4. Select a public exponent, typically denoted as e(public exponent) where 1 < e < totient(n) and e have to be coprime to totient(n). A coprime number is a number that has no common factors with another number besides 1. e is used to encrypt our message.

  5. The last step is to calculate the private exponent, typically denoted as d, where d * e = 1 (mod totient(n))

    Note that the public key, which is used to encrypt messages, is the pair of values (n, e). The private key, which is used to decrypt messages, is the pair of values (n, d).

    Now we have everything to encrypt our message. The encryption process is performed by raising the ciphertext to the power of the public exponent (e) and then taking the remainder when dividing by n. The decryption process involves reversing the encryption process. The recipient uses the private key (d) to raise the ciphertext to the power of d and then takes the remainder when dividing by n. This results in the original ciphertext message.

RSA Encryption in Internet Security Protocols: HTTPS, SSH, and VPNs

HTTPS, SSH, and VPNs are all internet security protocols that use RSA to provide secure communication.

HTTPS, or Hypertext Transfer Protocol Secure, is the secure version of the standard HTTP protocol used for web browsing. It encrypts the communication between a web server and a web browser using RSA, ensuring that any sensitive information, such as login credentials or credit card numbers, cannot be intercepted by an attacker.

SSH, or Secure Shell, is a protocol used for remote access to a computer. It encrypts the communication between the remote user and the computer using RSA, preventing attackers from intercepting sensitive information, such as login credentials.

VPN, or Virtual Private Network, is a technology that allows a user to securely connect to a remote network over the internet. RSA encryption is used to secure the connection, protecting the data transmitted over the VPN from being intercepted by an attacker.

In all cases, RSA encryption is used to provide secure communication by encrypting the data, and only the intended recipient with the private key can decrypt it. This ensures that even if an attacker intercepts the data, they will not be able to read it.

In conclusion, RSA is a widely used and trusted encryption method that is a fundamental part of many internet security protocols such as HTTPS, SSH, and VPNs. Its strength lies in the use of large prime numbers which makes it virtually impossible to crack the encryption. RSA is an essential tool for protecting sensitive information and ensuring secure communication over the internet.