Public Key Encryption(PKE)

#Cryptography #PKE

• Key Generation: $(sk,pk)\leftarrow Gen(\lambda )$

• Encryption: $c\leftarrow Enc(pk,m)$

• Decryption: $m\leftarrow Dec(sk,c)$

  • $Gen$ and $Enc$ are probabilistic (randomized) algorithms.

• Correctness: $m=Dec(sk,Enc(pk,m))$ for all key pairs, messages, and encryption randomness.

• Semantic security [Goldwasser-Micali '82] (for $m\in \{0,1\}$):

  • Distributions $(pk,E(pk,0)),(pk,E(pk,1))$ are indistinguishable (computationally hard to distinguish).