New Delhi, July 14: A combination of satellites, surveillance and software might have helped capture the words of suspect telephone conversations before or after the 7/11 blasts ' if Indian agencies had the resources.
While intelligence sources declined to reveal anything about India’s surveillance capabilities, scientists said existing technologies make it possible to selectively monitor telephone talk as well as email traffic.
A standard technique to selectively pick telephone calls or email is based on what scientists call “keyword-based filtering”. From a vast set of communication, only those that contain specific keywords are extracted for recording and analysis.
Academic research projects in India have led to the development of software tools that allow keyword-based selection of email from a large volume of traffic.
But the volume of communication, whether through telephone or email, is so large that surveillance capabilities are always limited by resources, a computer scientist who has worked on keyword-based software told The Telegraph.
Echelon ' a global interception system operated by the UK, the US, Canada, Australia and New Zealand ' is believed to have the capability to intercept telephone calls, fax or email messages sent to any individual anywhere on earth.
A European parliament committee set up to assess information about Echelon had said that its existence “is no longer in doubt,” and that “its purpose is to intercept private and commercial communications and not military communications”.
But the committee’s report said that even Echelon has limitations.
When communications are intercepted, no single telephone connection is monitored on a targeted basis. Instead, some or all of the communication transmitted via satellite or cable is tapped and filtered by computers using keywords.
“But filtering phone conversations on the basis of keywords is prone to errors and a lot harder than screening email with keywords,” said a scientist.
“The quality of voice may be poor. Accents will differ. Automatic word recognition hasn’t advanced enough. So phone conversation filtering requires a special software module that converts voice to text and then looks for keywords.”
The European parliament report says there are other factors that restrict the scope of filtering. “The ultimate capacity of computers, the language problem and, above all, the limited number of analysts who can read and assess filtered messages.”
“In such activities, the major hurdle is computing resources,” said a computer scientist. “Screening millions of communications day and night demands very fast computers, and that requires lots of resources.”
Software and other technologies to combat terrorism might also emerge from a new programme that India’s science and technology agencies might launch within weeks, science minister Kapil Sibal said.
Declining to provide details, Sibal said he wants science agencies to evolve a programme to fight terrorism with technology. “This would involve surveillance, software, and perhaps sensors for explosive detection,” he said.
While academic centres in India have pursued such technologies in the past, these efforts have been primarily driven by personal interests of faculty or their students. The proposed programme will bring together such scientists for a coordinated effort.