# Are there any asymmetric key encryption/decryption algorithms?

When it comes to encrypting some data (where data being something of a large size), symmetric key cryptosystem is predominant. Symmetric key algorithms like AES, DES, Blowfish, IDEA etc. are explained in greater lengths, on how they function and work and why is one better then the other.

But the same han't been done in the case of asymmetric cryptosystems. In general asymmetric cryptosystem is referenced, in a hybrid cryptosystem. Where the Symmetric key is used the encrypt the actual data, and then the Symmetric key is encrypted via the public key.

Even in the wikipedia page of RSA the emphasis is only given to the key exchange process of RSA, rather then how the actual data is encrypted/decrypted via it.

The most I know about Asymmetric key Cryptographic algorithms is that:-

• They are far slower then symmetric cryptographic algorithms;
• They produce cipher texts of sizes larger then the original one.

This is the only thing that is available when it comes to actual encryption / decryption by asymmetric algorithms. And even this hasn't been explained, why do they possess such behavior?

Even though they may not be a good choice, when compared with symmetric key algorithms, but still at least some information about their working should be provided.

EX:- In RSA, this is the description of the encryption process:-

    CT = (PT^E) % N

# where CT = Cipher Text, PT = Plain Text, N = Product of Two Large Primes, E = Public Key


But it has not be explained what happens in the encryption process.

I would like to get some intel on some asymmetric cryptographic algorithms used for encryption / decryption, so that I can analyze their internal working.

You are mistaken that there aren't any cryptographic standards that describe asymmetric encryption / decryption. You name RSA as an example and then you just show the modular exponentiation. However, in PKCS#1 - the predominant RSA standard - there are methods described to encrypt with a public key and decrypt with the private key. Currently it contains PKCS#1 v1.5 compatible padding (official name RSAES-PKCS1-v1_5) and OAEP (official name RSAES-OAEP). In the standard there are also some links to older standards that these schemes have been derived from.
• @VasuDeo.S It is not clear what you mean by why aren't the asymmetric key cryptographic algorithms explained to the level of detail as their symmetric key counterpart - did you read the standards linked by Maarten? If so, what part of it caused you to conclude that there is insufficient detail? What details are you asking about that are not present? – Ella Rose Jul 7 '19 at 15:23