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When we talk about data communication on the Internet, AES and RSA can be used as fine examples of encryption of data. The full form of AES is Advanced Encryption Standard, whereas RSA stands for Rivest, Shamir, and Adleman. Being popular data encryption methods, there is always a debate on AES Vs. RSA, and naturally so! However, the technicalities between the two are what makes them distinct and so popular encryption methods.
To understand RSA Vs. AES encryption let us get into the depth of each encryption method. Let us get started with RSA.
RSA is an algorithm used for secure data transmission. Widely used for securing data, it is one of the first practical public-key cryptosystems. The RSA algorithm is based on the fact that it is very difficult to factorize a large composite number into its prime factors.
There are three steps involved in the RSA algorithm. They are:
Key Generation: After generating 2 large prime numbers, they are multiplied. The two primes are kept secret while the product is made public. Another number, known as the public exponent, is also chosen.
Encryption: The sender searches for the public key of the recipient to encrypt a message. The public key contains the product of the primes and the public exponent. After finding the public key, the sender raises the message to the power of the public exponent, modulo the product of the primes. This process encrypts the message.
Decryption: For decrypting the data, the primes and private exponent is used. The recipient raises the encrypted message to the power of the private exponent, modulo the product of the primes. This process decrypts the message.
RSA is a widely used algorithm and is used in many different applications. Some common use cases of RSA include:
RSA is often used to encrypt messages, both in transit and at rest. For example, the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols maintain the security of communications that take place on web browsers and servers and key exchange too by using RSA.
RSA can be used to create digital signatures that can be used to verify the authenticity of a message. When a particular information is encrypted with a private key, the recipient can validate that indeed the owner of the corresponding public key has sent it. It is done decrypting the data with the public key.
RSA can be used to protect software and other digital content by encrypting it with a private key and requiring the user to provide a corresponding public key to decrypt and use the software.
RSA can be used to secure authentication in systems that require users to prove their identity. For example, in a two-factor authentication system, a user might enter a password and also prove possession of a private key by signing a challenge sent by the system.
RSA is also used in many payment systems. Banks and other financial institutions use RSA to ensure secure transactions and payments.
Most of the email-based services and programs leverage RSA for encrypting the message content and signing the emails. Thus, only the intended recipient is capable of reading them and they know that the recipient is certain that it was sent by a legit sender.
Read also about What is an RSA Certificate? How RSA Certificate Works?
Now let us check how AES works.
AES is a symmetric key encryption algorithm. Unlike RSA, which uses a pair of public and private keys, AES employs one key for encrypting and decrypting the data.
The AES algorithm works by taking a plaintext message and then applying a series of mathematical operations to it, called rounds, based on a fixed-length key. 128 bit, 192-bit, and 256-bit are AES key lengths. The more rounds and the larger the key size, the more secure the encryption. Each round applies a different, unique set of mathematical operations on the data, making it extremely difficult for an attacker to break the encryption.
AES encryption is used in a wide variety of applications due to its security, speed, and wide adoption. Here are a few examples of where AES encryption is used:
AES encryption is used in the security protocols of wireless networks, such as WPA and WPA2, to protect the wireless traffic between devices and the wireless access point.
AES is often used to encrypt the traffic sent over VPNs, which allows remote users to securely access a private network over the internet.
AES encryption is used in many file encryption and compression tools, such as WinRAR and 7-Zip, to securely encrypt files and protect them from unauthorized access.
AES encryption is often used to encrypt data stored in the cloud, to protect it from unauthorized access and to comply with regulatory requirements.
AES encryption is used in hardware security modules (HSMs), which are specialized devices used to secure cryptographic keys and perform cryptographic operations.
AES encryption algorithm is also used to encrypt data sent over SSH, which is used to securely access remote servers.
Other general encryption uses include security protocols and standards such as IPsec, SSL, TLS, and encrypting disk partitions, mobile devices, and other storage media.
Now lets us get into the differences between AES and RSA encryption methods.
AES and RSA are two widely-used encryption algorithms. Here are some parameters in which we have explained AES Vs. RSA encryption. Though both algorithms secure data, they are used in different ways and for different purposes. Let’s discuss RSA Vs. AES.
AES is a symmetric key algorithm, which means that only one key is employed for encrypting and decrypting data. It can be used with key sizes of 128, 192, or 256 bits. Apart from that, AES is considered to be a secure and fast encryption algorithm and is widely used in various areas like including VPNs and disk encryption software.
RSA, on the other hand, is an asymmetric key algorithm, which means that it uses a pair of keys, one that encrypts and one that decrypts. The encryption key, also called the public key is freely distributed, while the decryption key, or private stays confidential. RSA is commonly used in digital signature and key exchange, such as SSL/TLS used in https.
Another key difference is that AES is a block cipher which means it encrypts the data in fixed-size blocks (128 bits), while RSA is a public-key encryption system, RSA encrypts the session key that is used to encrypt data instead of the data itself.
While RSA is widely employed for key exchange or digital signature, AES is mainly used for data encryption. The latter is faster and more efficient than the former. However, RSA is generally considered to be more secure for digital signature and key exchange because it is done on the basis of the difficulty of factoring large numbers.
For a better understanding of RSA Vs. AES encryption, refer to the table below.
|Type of Crypotography||Asymmetric||Symmetric|
|Application of keys||Different keys are used for the purpose of encrypting and decrypting data||For the encryption and decryption of data one same key is used.|
|Block Size||Minimum 512-bit||128-bit|
|Key Length||1||10–128 bits, 12–192 bits, 14–256 bit|
|Security||Less Secure||Highly Secure|
RSA and AES are both encryption algorithms. However, they are used for various purposes and have some key differences. In summary, AES is good for encrypting data, while RSA is good for digital signature, key exchange or encryption/decryption of symmetric keys like AES.
Read also about SSH Vs. SSL – The Technical Differences Explained