Key-Value Data Collection with Distribution Estimation under Local Differential Privacy

Table 1

Notations.

Symbol	Description
	Domain of key-value data
	Key-value data set of user
	Domain of the key,
	Domain of the padded key,
	Domain size of the key
	Padding length
	Domain size of the padded key,
	Vector encoded by sampled key-value pair
	Randomized output vector
or	The -th element of vector or
	The key of
	The value of
	The perturbed key of
	The perturbed value of
	True frequency of the key
	Estimated frequency of the key
	Postprocessed frequency of the key