Abstract:
For Shamir's secret key sharing algorithm,
we develop the procedure for detection of faulty shares. This
procedure consists of the error locator polynomial construction
for the data set $ \{ (x_j,y_j)\}_{j=1}^N $ with $ y $ values
generated from $ x $ ones by a polynomial interpolant of a degree
$ n < N-1 $ with possible occurrence of some errors. The error
locator polynomial is sought out in the form of an appropriate
Hankel polynomial
$$
\mathcal H_{L}(x;\{ \tau \}) := \left|
\begin{array}{lllll}
\tau_0 & \tau_1 & \tau_2 & \ldots & \tau_{L} \\
\tau_1 & \tau_2 & \tau_3 &\ldots & \tau_{L+1} \\
\vdots & \vdots & \vdots & & \vdots \\
\tau_{L-1} & \tau_{L} & \tau_{L+1} & \ldots & \tau_{2L-1} \\
1 & x & x^2 & \ldots & x^{L}
\end{array} \right| \, ,
$$
where $ \tau_{\ell} := \displaystyle \sum_{j=1}^{N} y_j \frac{x_j^{\ell}}{W^{\prime}(x_j)} $; $ \displaystyle W(x):=\prod_{j=1}^N (x- x_j) $.