IBMRTD-L:an Identity-based Threshold Decryption Scheme Based On Lattice

In recent years,many scholars have proposed various threshold decryption schemes,either based on elliptic curve or bilinear pairings,which allow multiple users to decrypt ciphertext collaboratively.This method is more efficient and reasonable than the traditional method of encrypting plaintext to multiple receivers.Some of the certificateless schemes also solve the problem of public key verification,but the bilinear theory requires a high time cost.With the rise of quantum computing,the problem of discrete logarithm based on group or elliptic curve can be solved,and lattice cryptography,which is expected to resist quantum attacks,has attracted much attention.In this paper,we propose a certificateless multi receiver threshold decryption scheme based on lattice cryptosystem.The performance analysis shows that the scheme has relatively low computational cost in the process of encryption and decryption.The security analysis shows that the scheme is ind-cpa secure and can resist quantum attack under the random oracle model.