A Dynamic Searchable Symmetric Encryption Scheme for Multiuser with Forward and Backward Security

Table 1

Notations (used in our scheme).

Notation	Description
	A secure keyed PRF used to generate the key for algorithm
	A secure keyed PRF used to generate the key for algorithm
	A secure PRF family used to generate the file's column
	Maximum number of files corresponding to security parameters
	A secure keyed PRF used to generate the key of column
	A secure PRF used to generate the keyword's hash
	A secure PRF family used to generate the row order of keywords
	The set of keywords extracted from the file
	The set of files
	To column c of the index
	The key corresponding to column c of the index
	The ciphertext of the file corresponding to the cth column of the index
	The ciphertext of the set of the files
	The ciphertext of the set of the files F at time
	Plaintext of row of index at time
	The input label of HMAC
	The file set that does not update
	At time , the plaintext of the file corresponding to column of index