© Ravi
Visvesvaraya Prasad, May 2000. Reproduction strictly prohibited and
will be prosecuted without warning.
Published in The Telegraph, Calcutta, India on Wednesday, 17 May 2000, on the Edit Page. Go to http://www.telegraphindia.com Click on Archives and go to issue dated 17-05-00. Click on Editorial. Then Click on Electronic Tap Dancers |
||
The
Hansie Cronje episode has focused attention on tapping of cellular phones.
Whereas North American analog cellular systems such as AMPS and TACS can
be tapped easily using inexpensive scanners sold in stores, it was thought
until a few weeks ago that digital GSM cellular calls were relatively
immune to interception. GSM
base stations and message switching centers encrypt calls and assign
temporary identities to the sender and receiver. Since the rollout of GSM
in 1992, its encryption algorithms A 5(1) and A 5(2) had withstood all
attempts at cracking. It was thought that GSM calls could not be
intercepted while in transit between the originating base station and the
destination base station. The only two times that GSM calls were thought
to be somewhat vulnerable were first, between the initiating handset and
its closest six base stations, and second, between the destination base
stations and the recipient’s handset, both of which are short distances.
To intercept and decode a GSM call, it would be necessary to install
special equipment at the base stations and message switching centers (this
is what was done in the Cronje instance) which would require the
participation of the service provider and could realistically be done only
by law enforcement authorities. As installed in Delhi, this equipment can
listen in on only 180 conversations at a time but it costs over thirty
million rupees. Many
intelligence agents were surprised when evidence emerged a few weeks ago
that even the strongest version of the GSM encryption algorithm, A 5(1),
was vulnerable. In January French intelligence agencies succeeded in
tapping the GSM phones of British defence officials in Southeast England
through ten listening posts on the northern coast of France. This was a
remarkable feat for two reasons. The first was that the distance involved
was over 75 kilometres whereas GSM cell sizes are only a few kilometers
across. Further, the output power of the French listening posts was very
low to escape detection. Second, it appeared that the French had managed
to crack the A 5(1) algorithm. With
this, the French took their revenge on the Anglo-American intelligence
initiative, codenamed ECHELON, which uses its Chicksands, England,
facility to eavesdrop on French government officials (in particular the
French delegation to GATT in 1993) as well as on French defense
contractors such as Thomson CSF and Dassault. In 1995, ECHELON intercepted
communications between Airbus Industrie and the Saudi government. It
passed the information on to Boeing and McDonnell Douglas, who then came
in with a lower bid and won a $6 billion order. The
UKUSA agreement of 1947 created the global interception system, ECHELON,
which captures and analyzes phone calls, faxes, emails and telexes
transmitted over microwave links and all satellites. It is run by National
Security Agency (NSA) of USA, Government Communications Headquarters (GCHQ)
of UK, Communications Security Establishment (CSE) of Canada, Defense
Signals Directorate (DSD) of Australia, and Government Communications
Security Bureau (GCSB) of New Zealand. Germany, Japan, Norway, South Korea
and Turkey provide locations for listening posts, but have no other say in
the alliance. Indian
domestic and international communications, as well as INSAT satellites,
are targeted by the joint NSA/GCHQ listening post at the Indian Ocean
atoll of Diego Garcia, as well as by DSD stations at Geraldton and Bamaga,
Australia, and GCSB stations in Waihopai and Tangimoana, New Zealand. ECHELON
intercepts about 3 billion satellite transmissions, phone and fax calls,
e-mails, VHF and UHF radio communications, cellular and paging signals,
mobile data links, Internet downloads, and telemetry transmissions every
day. It records these transmissions, amounting to over 65 per cent of the
world’s telecom traffic, indiscriminately and then sifts through them
using a set of voice recognition, optical character recognition (OCR) and
data recognition artificial intelligence programs and context engines,
codenamed DICTIONARY, to find matches to a lexicon of keywords, phrases,
phone numbers, and names of individuals and places. While
the accuracy of detecting keywords is above 99 per cent for emails and 90
per cent for fax messages, it is only about 55 per cent for verbal
conversations. According to NSA’s former director Vice Admiral William
Studeman, if 1000 genuine keywords appeared during an hour's conversation,
there would be at least 300 missed key words, plus 220 false alarms.
He added that about ten messages per million are considered
significant enough to be analyzed further. Since
most terrorists would obviously not utter words like “assassination”
and “bomb” but would refer to these indirectly, NSA recently developed
a system using N-gram statistics to identify the topic of a conversation
even if the listed keywords are not used. Surprisingly NSA applied for a
patent (US patent application number 5937422 of 15 April) although this
would entail its having to make details of the system public. NSA claims
that its N-gram system would work for any language. NSA
had earlier patented a program called VOICECAST in May 1995 (US Patent
number 5418951) which can recognize an individual’s characteristic voice
patterns using Hidden Markov Modelling statistics, so that every call made
by that particular person can be transcribed. However a leading authority
stated that the accuracy of VOICECAST in recognizing the voices of
suspected Middle Eastern terrorists was only 15 per cent. In one amusing
instance a Canadian diplomat’s wife was investigated because she told an
Arabic friend on her cell phone: “My son really bombed in the school
drama yesterday.” However,
ECHELON may lose its effectiveness in coming years due to two reasons. The
first is that telecom carriers are shifting away from satellite and
microwave communications to optical cables, due to the much higher
bandwidth and immunity to interference that optical cables provide.
Optical cables cannot be tapped since they do not leak radio frequency
signals. Unless the optical cable passes through a collaborating nation,
the only place where these signals can be intercepted is at the
optoelectronic repeaters. Gaining physical access to these sealed
repeaters is not easy since they would be in hostile countries or
undersea. Moreover, the intercepting equipment would require its own
heavy-duty power supply. The
second reason is the increasingly wide availability of encryption systems
despite US export controls. Companies such as Hushmail and ZipLip provide
encrypted e-mail accounts to anyone anywhere in the world for free. At
current levels of decryption technology, it would take NSA several days to
decrypt e-mail messages sent to or from these accounts. ECHELON
has also been affected by budget cuts following the end of the Cold War.
It has started purchasing most of its equipment from commercial vendors to
cut costs. Its two major suppliers of transponder survey equipment (which
identify and classify satellite downlinks), demodulators, decoders,
demultiplexers, microwave radio link analysers, link survey units, and
carrier analysis systems are Applied Signal Technology of Sunnyvale,
California and IDEAS Operation of Columbia, Maryland. The proposed nationwide datacommunications network, Sankhya Vahini, has been attacked by politicians ranging from the Rashtriya Swayamsevak Sangh, the Congress, to the communist parties as being a security threat. On the contrary it will enhance India’s security since it is an optical cable network with end-to-end encryption. Thus it is not vulnerable to interception by ECHELON, in stark contrast to the vulnerability at present of INSAT satellites, VSNL’s gateways and DoT’s intercity microwave links. It is also good for our security that in coming years increasingly larger percentages of India’s overseas communications will take place through international optical cable systems such as SEA-ME-WE, FLAG and Project Oxygen and less through INSAT and Intelsat satellites. However, calls made to and from cellular phones will continue to be vulnerable as will the supposedly secure radio sets that are used by our National Security Guards, the Special Protection Group, and other paramilitary and security organizations.
Ravi Visvesvaraya Prasad Published in The Telegraph, Calcutta, India on Wednesday, 17 May 2000, on the Edit Page. |
||
Published in The Telegraph, Calcutta, India on Wednesday, 17 May 2000, on the Edit Page. Go to http://www.telegraphindia.com Click on Archives and go to issue dated 17-05-00. Click on Editorial. Then Click on Electronic Tap Dancers Reproduction of any portion of
the above article in any manner, including paraphrases, rewording, translations, abridgements,
excerpts, etc., in any medium, in any jurisdiction, in any language, for
any purpose, without the prior written permission of both Ravi
Visvesvaraya Prasad and The Telegraph, is strictly prohibited, and will be
vigorously prosecuted in criminal and civil courts without any prior warning. We continuously monitor the contents of the Web
as well as all downloading and copying operations from our web-site for violations of our copyrights. |
Ravi Visvesvaraya
Prasad & Associates |
We
represent multinational vendors of telecom and datacom equipment and services
in India.
We
have marketed telecom and datacom equipment and services to Indian basic
telecom operators, GSM cellular mobile operators, Internet service providers,
VSAT service providers, POCSAG paging operators, software exporters, etc.
We specialize in sales to the Department of Telecommunications (DoT), Videsh Sanchar Nigam (VSNL), Mahanagar Telephone Nigam (MTNL), large organizational customers, and private service providers. We obtain all regulatory permissions and licenses from central, state and local governments, obtain type approvals and interface approvals from the Telecom Engineering Centre, perform public and media relations, and introduce our clients to influential government officials, politicians, and print and television journalists. We perform customer requirements analysis, project feasibility analysis, return-on-investment analysis, risk analysis, financial closure, identification of joint venture partners, due diligence, contract negotiations and documentation. We have provided such advisory services to equipment suppliers, basic telecom operators, GSM cellular mobile operators, Internet service providers, VSAT service providers, POCSAG paging operators, radio trunking operators, etc. We market GSM cellular handsets of most major international brands at the best rates in North India.
|
|