PPSEB: A Postquantum Public-Key Searchable Encryption Scheme on Blockchain for E-Healthcare Scenarios

Algorithm 3

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Input: set , current time period , secret key in current period
Output:
(1)	Set a binary string , where is the security level of test in medical data cloud storage
(2)	Select a unitive matrix of dimension
(3)	Select noise through
(4)	Set
(5)	Select each noise vector on the basis of
(6)	Set the noise vector matrix
(7)	Assume and then compute and as ciphertext
(8)	Set ciphertext
(9)	Return to doctor