By David Ljunggren OTTAWA, Oct 27 (Reuters) - Western intelligence agencies "increasingly risk going deaf and blind" in the fight against terror because they find it hard to keep up with rapidly advancing technology, the head of Canada's spy service said on Friday. Jim Judd, director of the Canadian Security Intelligence Service (CSIS), said militants had access to a dizzying array of high-tech methods to plot attacks, pass on information and disguise themselves. "The pace of change in technology, particularly in telecommunications, is challenging the capacity of both intelligence and law enforcement agencies to maintain effective ... interception capacities," he said in a speech. "We increasingly risk going deaf and blind in an environment where telecommunications providers regularly change their systems to cater to the interests of their customers by improving service but in the process can literally leave us out of the loop, as the changes are unregistered." CSIS and the Royal Canadian Mounted Police worked closely together in a major operation earlier this year, which ended in the arrest of around 20 people who have been charged with planning terror attacks in the province of Ontario. The alleged plot -- as well as the bombing of the London transport system last year -- underlined the threat posed by citizens and long-term residents of western countries who become radicalized, Judd said. "The process of radicalization is one that we and other intelligence services do not yet -- in my opinion -- fully understand but one which is clearly troubling for many of us," he said, adding that the Internet played an important role in attracting recruits. "When the foreign leadership and direction of al Qaeda ... is combined with the efforts of radicalized citizens of western countries, the results could be potentially ferocious." Judd, who declined to take questions from reporters afterward, said intelligence agencies also had to deal with the power of the Internet and sophisticated software. "The use of publicly available encryption, steganography (the art of writing hidden messages), password-protected Web sites, chat rooms, the equivalent of Internet dead-letter drops and other techniques are in sum making an already difficult communications interception program even more problematic," he said. "Virtually all of these challenges are going to be further exacerbated in the future as the western world in particular moves increasingly into the domain of wireless Internet access and the use of technologies such as voice over Internet protocol (making phone calls using Internet technology)." Another challenge, Judd said, was the substantial growth of very high quality false identity documents which allowed militants to move around the world without raising suspicion. "It remains an open question I think as to whether new advances in biometric technology (designed to produce more secure passports) are going to help us control this phenomenon," he said. Judd -- who also complained about growing foreign espionage in Canada -- said CSIS needed a broader range of analytical skills as well as the ability to search data for signs of underlying trends and patterns. He also recommended that Canada should increase its presence abroad. Ottawa does not have a separate foreign spy agency but CSIS agents do sometimes work overseas on assignment, including Iraq and Lebanon, Judd said.