 Hi, I'm Ren Shizhen, and I will briefly introduce our new paper compact and tightly selected open SQL public key encryption scheme. This is joint work with Judging Pine. And in the PKE setting, we have a receiver, and the receiver has a public key and secret key. The send, we have a loss of senders, and they can use the public key to increase the message with some renderers, and then send the cybertext to the receiver. We consider setting that now the sender's renderers and message will be revealed to some adversary. And because the adversary gets the message and renderers, it can completely break the security of the cybertext. We say a cybertext is open, if its renderers and message are both revealed. So now some cybertexts are open, and we will ask how about the unopened cybertext. So the unopened cybertext remains secure, and the sender's selected open security considers such setting, or shortly, SO security. In the SO security, the adversary gets a bunch of challenge cybertexts, and it can also open some of the challenge cybertexts. The SO security requires that the unopened challenge cybertext remains secure. SO security is a very practical notion. For example, sometimes the sender's computer may be corrupted by some hacker, and the hacker can get all the information about the sender, including messages and the renderers. Or the sender can maybe use some insecure renderers generator, and the adversary can recover such insecure renderers. The selected open security has been studied for a long time, and it can date back to the 1999. There are two flavors of SO security notion, in distinguished ability-based SO security, and a simulation-based SO security, or shortly, SIM SO security. In this work, we just focus on the SIM SO security. And turns out that the SIM SO security is strictly stronger than the standard PKE security notion, like the INDCCA, and it's highly non-trivial to achieve SIM SO security, because there's a dilemma. If you want to put security, we should invest some problem instant into the cybertext. But if we embed the instance to the cybertext, then we can open the cybertext, because we do not have the renderers. And for example, one may wonder if we can use the hybrid argument plus an INDCCA SQPKE to achieve the same SO security. If such hybrid argument doesn't work, because if we want to use the hybrid argument to switch the chart in the cybertext to a renderer, then we can open the cybertext. And of course, there's a trivial solution to deal with such a problem. We just guess which cybertext will not be opened by the adversary, but this solution is not very good, because there's some value of probability. Since the reduction may get around, and it leads to some non-type security. So we ask, can we have SIM SOCCA scheme with type security? The answer is yes, but it's not very satisfactory. Some group-based SIM SOCCA is with type security. They have long syntax or long public key. Long public key means that the group, the number of group elements in the public key is not a constant. It depends on the length of the message and long cybertext similarity. The drawbacks that the non-compact PKE, they have a very high communication overhead. So in this one, we want to solve this problem. Can we have a SIM SOCCA scheme such that it achieves the type security, compact public key, and compact cybertext at the same time? And we find this problem is very hard, and we want to relax some requirements. How about in the random oracle model? Can we have such a scheme in the random oracle model? Our paper gives a positive answer to this question. We propose three direct constructions and a generic construction. They are all compact and tightly SIM SOCCA skills in the random oracle model. There are some techniques used in our paper, but I'm not going to introduce them there. And our full talk will be given in the Thursday morning. And thank you for your attention. We also thank Vanity Wagner for his helpful comments.