Differential Privacy for Evolving Network Based on GHRG

Algorithm 1

Dendrogram construction based on adjustment (DCBA).

	Input：sampled dendrogram at time t, evolving graphs , privacy parameter , .
	Output：sampled dendrogram at time t + 1.
(1)	if the result of change-point detection of is true then
(2)	Initialize the Markov chain by choosing a random starting dendrogram ;
(3)	for Markov chain step do
(4)	Randomly pick an internal node r in ;
(5)	Pick a neighboring dendrogram of by randomly drawing a configuration of r’s subtrees;
(6)	Accept the transition and set with probability ;
(7)	end for
(8)	if equilibrium is reached then
(9)	Return the sampled dendrogram ;
(10)	end if
(11)	else
(12)	for each new node do
(13)	for each internal node u whose child nodes are leaves in do
(14)	regard s as u’child node and construct a candidate set of the new dendrogram;
(15)	compute the log-likelihood of each candidate ;
(16)	end for
(17)	sample the new dendrogram with probability proportional to from the candidate set;
(18)	end for
(19)	Return the sampled dendrogram ;
(20)	end if