[LINK] RFI: Skype Conversation Accessibility

[Stilgherrian]

On 30/3/08 12:21 PM, "Richard Chirgwin" <rchirgwin at ozemail.com.au> wrote:
> 3) Skype is supposed to be difficult to crack because of its proprietary
> encryption. On the other hand, given the processing model (which
> distributes call processing across Skype-connected nodes), I would
> imagine that a node would yield information about who called whom.

This is an important point that's often forgotten when talking about
intercepting people's communication. wile the golden egg may be gaining
access  the *content* of the communication, often the traffic analysis is
sufficient for the purposes -- knowing who spoke to whom, and when.

As a classic example, if Alice calls Bob with a 2-minute conversation, and
then Bob call a dozen other people in turn with a 10-second conversation
each, and this happens regularly, you can infer that Alice is passing on
orders to Bob who then issues the code-word for "Go!" to his people.

And of course the traffic information can be combined with other data to
build up the picture. If on the second Tuesday of every month Alice always
calls Carol ten minutes before making a cash withdrawal of $2000 and then
driving to some specific location, both Alice and Carol better have a pretty
convincing well-rehearsed and internally-consistent explanation to convince
any interrogator that they're not doing some business together.

Stil


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