Our motivation is to tackle the following problems. In a threshold scheme, the sensitivity of the secret as well as the number of players may fluctuate due to various reasons, e.g., the structure of the players' organization might be changed. A possible solution to this problem is to modify the threshold and/or change the secret. Moreover, a common problem with almost all secret sharing schemes is that they are ``one-time'', meaning that the secret and shares are known to everyone after secret recovery. This problem could be resolved if the dealer shares various secrets at the beginning, but a better solution is to dynamically generate new secrets in the absence of the dealer.
As our contribution, the well-known re-sharing techniques are analyzed in both passive and active adversary models. Subsequently, our solution for a dealer-free dynamic secret sharing scheme is provided. Finally, a new secret sharing protocol, as an applications of our dynamic scheme, is proposed.Category / Keywords: threshold changeability, secret changeability Date: received 5 Jun 2009, last revised 11 Dec 2011, withdrawn 23 Apr 2012 Contact author: mnojoumi at cs uwaterloo ca Available format(s): (-- withdrawn --) Version: 20120423:162844 (All versions of this report) Short URL: ia.cr/2009/268 Discussion forum: Show discussion | Start new discussion