[ISN] Massive search reveals no secret code in web images

From: InfoSec News (isnat_private)
Date: Wed Sep 26 2001 - 01:50:26 PDT

  • Next message: InfoSec News: "[ISN] A TV Plea to Patriot Hackers"

    15:56   25  September 2001 
    Will Knight 
    New research indicates that terrorists are not using advanced computer
    tools to hide messages in innocuous-looking web images.
    In February 2001, US agents suggested that terror groups, including
    Osama Bin Laden's al-Qaida organisation, were hiding messages in web
    images. The FBI has suggested that recent terrorist atrocities in the
    US could even have been co-ordinated using images uploaded to ordinary
    internet sites such as eBay.
    Now Niels Provos and Peter Honeyman of the University of Michigan have
    found strong evidence suggesting such steganography - the science of
    obfuscating communications - is not used. They used detection software
    and brute force computing power to scan millions of images posted to
    the internet and found no hidden messages.
    "We have analysed over two million images downloaded from eBay but
    have not been able to find a single hidden message," they write in
    their paper, Detecting Steganographic Content on the Internet.
    Redundant code 
    Messages can be hidden within redundant parts of the digital
    information used to generate images in formats such as JPEG. This
    offers advantages over encryption, which only hides the meaning of a
    message, because the message itself disappears.
    Provos and Honeyman ran computer programs to analyse the digital
    information behind images and identify any portions that might have
    been altered. They further checked these portions to see if any
    changes could be explained by normal copying errors.
    The pair employed a bank of distributed computers to check through
    millions of images. After weeks of analysis, however, they found no
    hidden messages.
    Extra layer 
    The technique may not be infallible. The methods used by Provos and
    Honeyman were particularly aimed at uncovering use of steganographic
    tools already released on the internet.
    There are more advanced methods of hiding communications within images
    that involve using active, as well as redundant parts, of the
    underlying code. Sushil Jajodia of the Centre for Secure Information
    Systems at George Mason University in Virginia, US, says that this
    could have evaded detection but would require considerable technical
    Jajodia says that a message might also be encrypted before hiding.
    "This would add an extra layer of security," he says. But he also
    stresses that there are far simpler methods for hiding communications.
    Using a code word in a telephone conversation or a radio broadcast
    would provide a far easier way to communicate in secret, he says.
    Magnus Ranstorp, of the Centre for the Study of Terrorism and
    Political Violence at the University of St Andrews in the UK, agrees.
    He told New Scientist: "These groups do use encryption, but some of
    the most important information is relayed non-technologically, it is
    often carried by human couriers."
    ISN is currently hosted by Attrition.org
    To unsubscribe email majordomoat_private with 'unsubscribe isn' in the BODY
    of the mail.

    This archive was generated by hypermail 2b30 : Wed Sep 26 2001 - 09:11:47 PDT