Authors: Sirapat Boonkrong
Abstract: Online social networks have become an essentialtool for communications these days. With popularity comesecurity problems, especially with information privacy. Oneway to solve this problem is to use cryptography. However,cryptography on online social networks has not been studiedexclusively. Most works have been done on access control.The main issue with cryptography is the number of keysneeded to encrypt and decrypt the information. The mostobvious number of keys would be to use one key for everyuser in our group of friends. This is not entirely true as weshow here. This paper, therefore, gives an attempt to showthat the number of keys needed to achieve secure sharingamong friends can in fact be fewer than the number offriends. We also provide proofs of correctness and security toconfirm our claim.
Keywords: social networks; security; cryptography; keys;proof of correctness