On Single Share Assignment Threshold Schemes

• Main Authors: Chang-Che Hwang, 黃章哲
• Other Authors: Gwo-Bao Horng
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/42892298202268676878

碩士 === 國立中興大學 === 資訊科學學系 === 83 === Secret-Sharing plays an important role on information- al security. For some useful cryptosystem, we provided the master key for these important. So we must keep the master key integrated and safe to avoid malignant destruction. If the master key is lost or destoryed, the information w- hich provided by the master key will become untrust-worthy . Therefore, how to protect the master key is an important course in key management. In the thesis, we consider the problem for given the authorized access structure to find the all threshold. We generalize the shamir's threshold scheme to general ac- cess structures in such way that each participant holds o- ne share. Such new schemes are called the single share as- signment threshold scheme. We give a sufficient condition for an access structure to allow such schemes to exist. We also give a necessary condition for an access structure to allow such schemes to exist. We also show how to const- ruct weak single share schemes for general access structu- es. For single share assignment threshold scheme, we prop- ose the algorithm which satify the sufficient condition to find a group-sequence. Finally, we give an application for the fault tolerance in network by using I.D.A.(Information Disperal Algorithm).