Table 2: Homomorphic encryption cryptosystems.

CharacteristicsRSAPaillierElGamal

PlatformCloud computingCloud computingCloud computing
Homomorphic typeMultiplicativeAdditiveMultiplicative
Asymmetric in natureYesYesYes
Data privacyAll ensures privacy both in communication and storage (data at rest)
Data securityYesYesYes
Key used bySeparate keys are used for encrypt/decrypt either by customer/provider
Speed (enc/dec)Fast/slowSlow/slowSlow/fast