  Quantum Cryptography is a rapidly developing field of research that benefits
from the properties of Quantum Mechanics in performing cryptographic tasks.
Quantum walks are a powerful model for quantum computation and very promising
for quantum information processing. In this paper, we present a quantum
public-key cryptographic system based on quantum walks. In particular, in the
proposed protocol the public key is given by a quantum state generated by
performing a quantum walk. We show that the protocol is secure and analyze the
complexity of public-key generation and encryption/decryption procedures.
