On Key Escrow System for One-way and Two-way Communications

• Main Authors: YANG TAI YUEH, 楊泰岳
• Other Authors: Chiu, Jung-Hui
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/50738372285983301442

碩士 === 國立臺灣科技大學 === 電子工程系 === 88 === The LEAF arrangement of conventional key escrow systems confines LEA can only listen from the transmitter. So, when the suspect is the receiver in a one-way communication, LEA cannot get the suspect’s receiving message. When communication system allows both users decide their session key differently in a two-way communication, LEA cannot get the conversation. Due to the confinements described above, conventional key escrow systems do not listen secretly in a suspect- -oriented way. Because it is difficult to revise former systems to be suspect-oriented, we built a new KES to meet the following needs: (1) To be suspect-oriented. LEA can intercept communication at suspect’s end and recover message solely by suspect’s secret key components returning from KEAs. (2) LEA can get the information in both one-way and two-way communication. Even both users decide their own session keys in a two-way communication, LEA can get the whole contents. (3) LEA can only eavesdrop in an authorized duration. (4) This system stipulates a threshold to recover user’s secret key. LEA can calculate interim value while waiting KEAs’ returning values, and can get session key after the number of returning value is over the threshold. (5) This system can resist key conversion attack, squeezing attack, and bogus LEAF attack. (6) This system can protect user’s secret key from revealing to LEA, KEA, and KMC.