I went reading the linked intro to Fully Homomorphic Encryption [1]

>This means you can multiply together any two Elgamal ciphertexts, and upon decryption you’ll find that the (single) resulting ciphertext now embeds the product of the two original plaintexts. Neat!

Coolest thing I've read in a while.

[1]-https://blog.cryptographyengineering.com/2012/01/02/very-cas...