A CBI judge on Friday said India is yet to sign a treaty with other countries to extradite accused involved in cyber crimes.

"Till date, we do not have a single treaty with any other country to extradite a cyber criminal to be brought to India," CBI special judge, New Delhi, Talwant Singh said at a seminar.

He said the Indian Penal Code is applicable for a crime committed in India. "Our Cyber law simply says that if there is an incident in India and whether it was committed from any other country, he (the accused) is still a criminal in the eyes of the (Indian) law," he said.

He said India has physical boundaries in terms of its geographic location with other countries, but there was no such 'boundary' in cyber world. "Our cyber boundary is not (yet) defined. We have to protect our cyber boundaries also."

He said at the time of 26/11 terror attacks in Mumbai, there was no proper definition of cyber terrorism in India.

Terming cyber terrorism a "heinous crime", he said, notification (from government) was still awaited for setting up an infrastructure to protect vital information on national security.

Referring to the Delhi Metro Rail project, he said it was run by computers and if it comes under cyber attack, who would be authorised to "turn it off"?

"It remains unclear if response to cyber attack includes authority to shut down a computer network, even if it's been taken over by a malicious cyber attacker with an intention to destroy it," he said.

Laws, both at national and international level, were still struggling to catch up with cyber activities worldwide. "In most cases, laws have not kept pace with the technical ability of an adversary to move rapidly through national, academic, commercial and private internet service providers."

In conventional military terms questions such as how strongly a country can respond to a cyber attack when one does not know who did it, from where they did it and their intention, are easier to answer "but not so in the cyber world," he said.