Speech Encryption Scheme Based on Ciphertext Policy Hierarchical Attribute in Cloud Storage

Table 3

Symbol definition.

Symbol	Definition description
Au	A user’s set of attributes
	Attributes associated with ciphertext
L	The bit length of the element
	Number of elements
k	Number of files
n1	Number of rows of matrix M
|X|	The set of leaf nodes of the access tree in Reference [30]