Symmetric and asymmetric encryption using the same encryption/decryption algorithm?

ESCM

6/16/24, 4:57 PM

If we use the following notation:

$$C = E(P, K_e)$$

$$P = D(C, K_d)$$

Where: $$E(), D(), C, P, K_e, K_d$$ are the encryption algorithm, decryption algorithm, ciphertext, plaintext, encryption key and decryption key respectively

The only difference between symmetric and asymmetric encryption is:

$K_e = K_d$ for symmetric and $K_e \neq K_d$ foy asymmetric.

So in theory we could use the same E() and D() for both types of encryption.

My question is: Is this correct? And if so, are there real examples of this?

Also, if it is correct, why is it not so used? I suppose that the answer to this is due to the fact that making specific algorithms for each type of encryption(asymmetric and symmetric) could lead to a better efficiency(troughput, security level, encryption speed, etc) of them.

0 + 4

symmetric

kelalaka

6/16/24, 5:19 PM

Why do we need for slow encryption with asymmetric ciphers while we have fast block ciphers? There is one that uses modular arithmetic to achieve symmetic encryption, though still slow.

poncho

6/16/24, 5:29 PM

See https://crypto.stackexchange.com/questions/106782/are-asymmetric-encryption-and-decryption-same-function/106783#106783 for an answer in the assymetric case

kelalaka

6/16/24, 5:33 PM

[/pohlig-hellman](https://www.rose-hulman.edu/~holden/Preprints/pohlig-hellman.pdf)

DannyNiu

6/17/24, 8:20 AM

"Also, if it is correct, why is it not so used", It's not so used FOR THE EXACT REASON OF it being incorrect!

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Symmetric and asymmetric encryption using the same encryption/decryption algorithm?

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