> Date: Fri, 19 Sep 2003 11:57:22 -0400 > From: Ian Grigg <[EMAIL PROTECTED]>
> If I understand this correctly, this is both > an eavesdropping scenario and an MITM scenario. > > In the above, Eve is acting as Mallory, as she > is by definition intercepting the bits and re- > sending them on? As Dave Howe pointed out, Eve is acting as a repeater and tries not to alter the bits. This seems a sensible model of eavesdropping for QKD. The threat is that Alice and Bob might incorporate bits that were seen by Eve into their key. If Bob never receives a bit, it won't be used. > That is, the "Quantum Property" is that Eve can > be detected because she destroys photos in the > act of listening, and Mallory, who can resend > the photons, has only a 50% chance of reading > each bit correctly in advance, so he can be > detected after the fact as well, as 25% of his > bits are wrong. The terminology "destroy" is used a bit loosely. I think the important thing for QKD is that if a photon is measured with the wrong basis, the information it is carrying about the key is lost. Ray --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]
