Ches is known for his early work in Internet security, including firewalls, proxies, and as co-author on the first full book on Firewalls. He is also noted for his work in visualizations, especially Internet maps, which have appeared widely. Ches has worked at Bell Labs and AT&T Shannon Lab, and was a cofounder of Lumeta Corp.
He continues to invent, collaborate, write apps, consult, and give talks worldwide. He is a visiting scholar at University of Pennsylvania.