What is an RSA Certificate: How RSA Certificate Works?

The use of strong encryption algorithms is an essential tool for ensuring the security and privacy of information in the modern world. Therefore, when we talk about encryption, mentioning RSA certificates is inevitable.

Today, it is a widely used asymmetric encryption algorithm. In this post, let us learn about SSL/TLS certificates equipped with the RSA algorithm, aka an RSA certificate.

RSA online certificate is commonly used in electronic commerce protocols and for digital signature generation and verification. It is also used in many software protection systems to ensure only authorized users can access the protected software.

Let us find out what it is.

What are RSA Certificates?

RSA stands for Rivest Shamir Adleman. This cryptographic algorithm is named after its inventors of this cryptographic algorithm- Ron Rivest, Adi Shamir, and Leonard Adleman.

These types of SSL certificates use RSA encryption to secure data transmitted over the internet. They are used to establish a secure connection between a web server and a client and to verify the website’s identity. They are commonly used in HTTPS, the secure version of the HTTP protocol used on the internet.

RSA is a public-key encryption algorithm considered a standard for sensitive data encryption.

Features of RSA

Asymmetric Encryption: RSA uses two keys, one for encryption and one for decryption. As the encryption key is made public and the decryption key is kept private, it helps establish secure communication between two parties.

Key Size: RSA keys can be generated with key sizes of 512, 1024, 2048, and 3072 bits. The larger its size, the more secure the encryption is.

High Security: As it is based on the difficulty of getting two large and random prime numbers, no one can decrypt the data without a private key.

Digital Signatures: RSA is also used to create digital signatures, which are used to prove the authenticity of a message or document.

Now, let us see where RSA is used.

Secure Communication: RSA is often used to secure communication between two parties. It can be the RSA online certificate used in Transport Layer Security (TLS) web browsing and email protocols.

Code signing Certificates: These are used to verify the authenticity and integrity of the code. This ensures the code is not tampered with and comes from a trusted source.

Virtual Private Networks (VPNs): VPNs use RSA to secure communication between two parties and verify their identities.

Email: Some email clients and servers use RSA SMIME certificate to secure email communication and protect the privacy of messages.

File and Data Encryption: RSA can also encrypt files and data to protect against unauthorized access.

Various individuals and organizations use RSA encryption to secure communication and protect sensitive information.

Also Read: What is COMODO RSA Certification Authority?

Now, let us see how an RSA Certificate works.

How does an RSA Certificate Work?

RSA certificates use a pair of keys: a public key and a private key. Users utilize the public key to encrypt information, while the private key is employed to decrypt the encrypted data.

When a client-server connects to an RSA-enabled website, the website sends its public key to the client. The client then uses that public key to encrypt any information it sends to the website. It can be login credentials or credit card information. The website employs its private key to decrypt the information, enabling it to read and process the data.

The certificate also contains information about the website’s identity, such as the domain name and the organization that operates it. This information is verified by a certificate authority (CA) before the certificate is issued. This ensures that the certificate belongs to the website that it claims to belong to and that the website is who it says it is.

The algorithm is based on the prime factorization method for one-way data encryption. It involves two large random prime numbers being multiplied together. Developing a public key involves using the product of these two numbers, modulus.

Although the modulus is made public, the two prime numbers remain private, preventing anyone from determining the original message or data using the public modulus.

For the encryption and decryption of data, the RSA algorithm uses the principles of number theory and mathematical trapdoor functions.

The Encryption Process happens like this:

In this process, two large prime numbers, typically denoted as p and q, multiply together to form a modulus.

n = pq.

Afterward, the selection of e as a public exponent takes place. This step involves choosing a relatively prime number to n, which is calculated as (p-1)(q-1).

The modulus n assists in generating the private key by selecting another number, d, in such a way that (ed) mod (p-1)(q-1) = 1.

To encrypt a message, m, the sender raises it to the power of e mod n.

The decryption process happens like this:

To decrypt the message, the receiver raises the ciphertext to the power of d mod n. This process then results in the original message.

So, this is how the RSA algorithm works. But how safe is it? Let’s find out.

Is RSA Truly Safe?

RSA is a widely used and well-established encryption algorithm. For years now, the security of RSA encryption has been considered sound. One potential vulnerability is its use of key size for encryption.

It uses substantial prime numbers to generate public and private keys. The larger the critical size, the more secure the encryption.

However, as computational power increases, the possibility of factoring larger and larger numbers becomes possible with smaller key sizes. Thus, experts often recommend using larger key sizes, such as 2048 or 4096 bits, for RSA encryption.

Despite this, RSA remains a widely used algorithm for encryption. Always remember that encryption is only one part of a holistic security strategy and that other measures, such as proper key management and secure software development practices, are also crucial for maintaining the security of RSA encryption.

So get RSA certificates from the best CA and ensure 100% security on your digital certificates. You can go for the Sectigo SSL certificate or the Comodo SSL Certificate.

Concluding Words

The RSA plays a crucial role in securing data in transit over the internet and establishing secure communication channels between two parties. It is widely used as a public-key cryptography algorithm for this purpose.

It is based on the mathematical concept of factoring large integers. It has several important properties, including the ability to encrypt and decrypt data and sign and verify digital signatures.

You can go for the Sectigo RSA certificate or the Comodo RSA certificate. They both offer promising levels of security, and their RSA certificate price is also low.

Also Read: What is ECC SSL and Where to Get It?