A Study on the Security of Privacy Homomorphism

10.6633/IJNS.200801.6(1).05

Yu Yu；Jussipekka Leiwo；Benjamin Premkumar

Chosen-ciphertext attacks ； private computation ； privacy homomorphism ； semantic security

International Journal of Network Security

6卷1期（2008 / 01 / 01）

33 - 39

英文

Informally, Privacy Homomorphism (PH) refers to encryption schemes with a homomorphic property allowing to obtain Ek(a + b) or Ek(a × b) from ciphertexts Ek(a) and Ek(b) without the knowledge of the decryption key. Privacy homomorphisms, especially algebraic ones, have a wide range of applications in information security due to the homomorphic property. In this paper, we correct a misunderstanding regarding the security of additive PH, give a definition for efficient PH, and discuss the security of algebraic PH in the black-box model to show that any PH is at most semantically secure under non-adaptive chosen-ciphertext attacks (i.e. IND-CCA1 secure), which also implies that we can simulate an IND-CCA1 secure algebraic PH with a small amount of hardware.