  Recent advances indicate that quantum computers will soon be reality.
Motivated by this ever more realistic threat for existing classical
cryptographic protocols, researchers have developed several schemes to resist
"quantum attacks". In particular, for electronic voting, several e-voting
schemes relying on properties of quantum mechanics have been proposed. However,
each of these proposals comes with a different and often not well-articulated
corruption model, has different objectives, and is accompanied by security
claims which are never formalized and are at best justified only against
specific attacks. To address this, we propose the first formal security
definitions for quantum e-voting protocols. With these at hand, we systematize
and evaluate the security of previously-proposed quantum e-voting protocols; we
examine the claims of these works concerning privacy, correctness and
verifiability, and if they are correctly attributed to the proposed protocols.
In all non-trivial cases, we identify specific quantum attacks that violate
these properties. We argue that the cause of these failures lies in the absence
of formal security models and references to the existing cryptographic
literature.
