 Hi, everyone. I'm Chipan Liu from Simon's Institute. Today I will be talking about the work on the feasibility of unclonable encryption and more This is a joint work with Prabangjan, Fatih, Xinjian, and Mark. The talk is about using quantum information to do something interesting about cryptography And perhaps the most fascinating phenomena about quantum information is the unclonability It says a piece of quantum information cannot be cloned into two identical copies This so-called no-cloning theorem leads to a new exciting area about quantum cryptography Which we call an unclonable cryptography Here instead of building and analyzing the security of classical scheme against quantum computers We are interested in what quantum computer can bring us There are a line of work leveraging unclonability including quantum key distribution and quantum mining Among those one major area is to make classical crypto system unclonable This security says there's no way to copy a key or copy an identity or even a cybertext This is a way of enhancing the classical security even further. For example, achieving everlasting security And just like one-time-pad is the most fundamental primitive to cryptography One-time-symmetric key unclonable encryption is the simplest yet most important primitive we should consider The question was first proposed by Gosman and studied by Broadband and Lord Broadband and Lord considered the following security notion Encryption of a random message is given to an adversary and this encryption is a quantum state The adversary attempts to produce two cypher texts and later on keys are revealed The adversary wins if and only if both copied cypher texts can be used to recover the original message Broadband and Lord show that it is Actually possible either in information theoretically secure way or in the random or in the quantum random oracle model However, this is not the optimum security as it does not rule out the possibility that Adversary recovers non trivial information about the message for example They can maybe they cannot both recover the whole message that they can learn the first bit of the message simultaneously and They identify the problem, but they cannot give any security proof even with stronger assumptions like oracles and In this word we show that in the random oracle model the optimum security can be achieved The out the optimum security is defined with the CPA style That is the chosen plain text a text style in this security game a pair of messages are chosen by the adversary encryption of One of the message M0 or M1 is given to an adversary and it attempts to produce two cypher texts and later on It also will get the keys and the adversary wins if and only if it knows which messages are encrypted Independently using the the encryption and also using the key The probability should be very close to half intuitively it says Regardless of what clone strategy is used several texts can only go one way That is either go the upper pass or lower pass and the other encryption will be completely junk and this is our Main serum in the work. We show that there exists an uncolonable encryption scheme in a quantum random oracle model with optimum security we just mentioned before and we also have other result the first result is to justify our The use of random oracle with we prove that uncolonable encryption Cannot both cannot simultaneously satisfied Being information theoretically secure and also being deterministic in other words you to achieve the optimum security You need either computational assumption or you need the scheme to be randomized And we also show applications to copy protection for point functions This is everything I want to talk about today Please come to our talk in crypto 2022. Thank you