%0 Journal Article %T Experimental Eavesdropping Attack against Ekert's Protocol based on Wigner's Inequality %A F. A. Bovino %A A. M. Colla %A G. Castagnoli %A S. Castelletto %A I. P. Degiovanni %A M. L. Rastello %J Physics %D 2003 %I arXiv %R 10.1103/PhysRevA.68.034309 %X We experimentally implemented an eavesdropping attack against the Ekert protocol for quantum key distribution based on the Wigner inequality. We demonstrate a serious lack of security of this protocol when the eavesdropper gains total control of the source. In addition we tested a modified Wigner inequality which should guarantee a secure quantum key distribution. %U http://arxiv.org/abs/quant-ph/0308030v2