Editing Key generation (section)

===Wireless channels===
A wireless channel is characterized by its two end users. By transmitting pilot signals, these two users can estimate the channel between them and use the channel information to generate a key which is secret only to them.<ref>{{cite journal|author1=Chan Dai Truyen Thai |author2=Jemin Lee |author3=Tony Q. S. Quek |title=Physical-Layer Secret Key Generation with Colluding Untrusted Relays|journal=IEEE Transactions on Wireless Communications|pages=1517–1530|volume=15|issue=2|date=Feb 2016|doi=10.1109/TWC.2015.2491935|s2cid=27603548 }}</ref> The common secret key for a group of users can be generated based on the channel of each pair of users.<ref>{{cite conference |title=Secret Group Key Generation in Physical Layer for Mesh Topology |author1=Chan Dai Truyen Thai |author2=Jemin Lee |author3=Tony Q. S. Quek |date=Dec 2015 |book-title=2015 IEEE Global Communications Conference (GLOBECOM) |pages=1–6 |location=San Diego |doi=10.1109/GLOCOM.2015.7417477 }}</ref>