Generative Text Secret Sharing with Topic-Controlled Shadows

Algorithm 2

The recovery phase.

	Input:
	shadow texts ; row vectors corresponding to ; the number of secret units to be shared at one time ; height of perfect binary tree ; the topics of each shadow text ; bag of words related to .
	Output:
	Original secret bitstream .
(1)	Combine row vectors to obtain the recovery matrix , calculate the inverse matrix according to (3);
(2)	for each shadow text do
(3)	Input the prefix of into LM to get ;
(4)	while not the end of do
(5)	Based on , can be obtained through (6);
(6)	;
(7)	Input the last word of and into LM, then ;
(8)	;
(9)	Arrange the in descending order, encode the words by a perfect binary tree;
(10)	Extract the codeword corresponding to and transform it to integer value, which is the shared value . Then add to ;
(11)	for each in each do
(12)	Combine into vector , and calculate according to , the first elements are secret values, which are added to ;
(13)	Transform each value in into the binary form of bits, then is obtained;
(14)	return