A Comprehensive Survey on Local Differential Privacy

Table 2

Comparison of RAPPOR and its variants.

Method	Encoding	Longitudinal reports	Perturbing
Basic RAPPOR [7]	Unary (bit vector)	Multiple times	PRR + IRR
RAPPOR [7]	Hash unary (bloom filter)	Multiple times	PRR + IRR
One-time RAPPOR [7]	Hash unary (bloom filter)	Once	PRR
Basic one-time RAPPOR [7] (K-RAPPOR) [35]	Unary (bit vector)	Once	PRR
OUE [36]	Unary (bit vector)	Once	PRR (optimal parameters)
O-RAPPOR [35]	Unknown domain (bloom filter)	Multiple times	PRR + IRR