Multi-level access control method and system based on multi-secret visual password

The invention discloses a multi-level access control method and system based on a multi-secret visual password. The method comprises the following steps: 1) a server sets a corresponding secret imagefor each permission level in a control policy, and assigns a permission level to each user; 2) the server constructs a corresponding sharing matrix for each secret image, and then fills pixels in thesecret image into a plurality of shared shares of different levels according to the sharing matrix; 3) the server distributes the shared shares to users of corresponding permission levels according toa permission allocation policy, and the server keeps a minimum level shared share and the secret images; and 4) the server receives authorization requests and the shared shares issued by at least k-1users, and then performs secret recovery according to the received shared shares and the reserved shared shares, and identifies the authenticity of the shared shares to decide whether to authorize. By adoption of the multi-leve