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- Undercover communication
- It should be obvious by now, that the only way to communicate
- stealthily and securely is to avoid raising suspicion to the
- level at which the authorities might consider it worthwhile
- to put you under active surveillance (e.g., park a van with
- TEMPEST equipment by your apartment).
- It has long been my view that, if the authorities have enough information
- on you to enable them to park a surveillance van outside your home, then
- you have failed utterly, and the battle is already lost.
- Notwithstanding that, I still had to laugh at the story posted in Slashdot
- the other day about he kid who was being investigated who noticed that, when
- searching for WiFi connections, one of the SSIDs was "FBI SURVEILLANCE VAN".
- Moreover, the medium for such a communication must be the Internet,
- since since it is the only publicly available medium that has seen
- any serious development of anonymous and/or secure communication.
- Agreed.
- Let's go over some specific methods of clandestine information
- exchange over the net:
- Encrypted e-mail
- Although apparently secure, this method puts the communicating
- parties at great risk of detection. E-mail servers are centralized,
- and accounts are easily associated with message transmission times
- and locations. Once a single member of the communication network
- becomes suspect, the whole network is immediately exposed. This
- holds for all similar server-dependent protocols.
- Encrypted email does not prevent traffic analysis; it merely prevents anyone
- from trivially discovering the message contents. If you can be located, you
- can be compelled to decrypt your messages, whether through legal threats or
- the authorities simply beating the passphrase out of you -- so-called
- "rubberhose cryptography".
- The only way this can be avoided, is to periodically change one's encryption
- sub-key. If the old encryption sub-keys are securely destroyed, then the
- previous message traffic encrypted with those keys is not recoverable. Keys
- can be changed according to one's level of paranoia -- weekly, bi-monthly,
- monthly, quarterly, or randomly.
- E-mail accessed exclusively over onion routing
- This is a much better approach than just e-mail, but it is still
- susceptible to traffic analysis, and to control of the communication
- channel by an external party.
- Agreed.
- Usenet posts
- This is a good approach to clandestine communication. Since Usenet
- is a distributed system, traffic analysis is non-trivial, and
- messages can be steganographically hidden inside innocent-looking
- posts (e.g., SPAM) in some high-traffic unmoderated group. Many users
- will read the message, oblivious to its true contents -- thus protecting
- the message recipient from scrutiny.
- While I agree that the distributed nature of Usenet makes traffic analysis
- non-trivial, I completely disagree with the use of steganography to protect
- your traffic. For starters, the authorities are not unaware of the existence
- of steganography -- as such, it is really suitable only for rendering your
- message traffic oblivious to the greater public. Also, by disguising it as
- spam, it may be filtered-out by some news providers.
- If you're going to secure your messages, then the best way to do so is to
- use strong encryption. The best way to hide strongly-encrypted messages is
- to post them to a newsgroup where strongly encrypted messages make-up
- virtually all of the traffic in the group. If you're looking for such a
- secure, high-traffic group, you really need look no further than
- alt.anonymous.messages (a.a.m.) -- it was designed for this very purpose.
- Furthermore, as I relate in the example case below, any real volume of PGP-
- encrypted traffic in newsgroups other than alt.anonymous.messages /will/ be
- noticed.
- One of the most frequent uses for alt.anonymous.messages is as the target of
- nymserver reply-blocks. Use of such reply-blocks renders any nymserver email
- address untraceable, as the encrypted mail can be picked-up from any news-
- server that carries alt.anonymous.messages. Furthermore, there are utilities
- (e.g.aamfetch, available from sourceforge) that can be used to fetch all
- one's messages from alt.anonymous.messages making it impossible to determine
- precisely what messages are being retrieved.
- Nymserver accounts are setup/maintained by sending specially-constructed
- email messages to the nymserver. If these messages are sent via a chain of
- mixmaster remailers, even the nymserver operator cannot determine who owns
- a particular nymserver account, even if they were to start keeping logs,
- perhaps at the insistence of the authorities. If one uses a randomly-chosen
- chain of mixmaster remailers, then it is not possible to the authorities to
- compromise the remailers you are using -- in order to trace you, they would
- have to effectively compromise the entire mixmaster network.
- Accordingly, the only way a nymserver account holder can then be traced is
- through their reply-block associated with the account. If the reply block
- points to alt.anonymous.messages (a.a.m.), then the authorities will reach
- a dead-end. They will not be able to trace the nym account owner, nor will
- they be able to read their message traffic.
- Now, you might ask: "Just how secure is this setup?"
- You'd be surprised at just how effective it is -- it was enough to thwart a
- combined investigation by the FBI and the Australian Federal Police (AFP),
- the Queensland Police Service (QPS), Europol, Interpol, The Department of
- Internal affairs New Zealand, and the Toronto Police Service.
- Let me tell you a little story....
- In just a few days, it will be exactly 3 1/2 years ago, that the American
- Federal Bureau of Investigation (FBI), the Australian Federal Police (AFP)
- and the Australian Queensland Police Service announced the existence of
- "Operation Achilles" which led to the breakup of what they claimed was one
- of the largest child pornography rings uncovered up to that time.
- The individuals comprising this pedophile ring called themselves "the group"
- and they believed themselves untouchable, beyond the reach of the police.
- (For many of them, -- one-half to two-thirds, depending on which affidavit
- you believe -- this did, indeed, turn out to be the case. This includes the
- ringleader, who is known by the handle Yardbird.)
- The number of persons reportedly involved varied -- one affidavit stated
- that there were 61 persons involved, another 45, and yet another 48. All in
- all, there were 22 persons arrested: 2 in the UK, 4 in Germany, 2 in
- Australia, and 14 in the U.S.
- The FBI podcast, "Inside the FBI" states that the number of persons involved
- was 60, of which 22 were positively identified. You can listen to the podcast
- and read the transcript at the following URL:
- https://www.fbi.gov/news/podcasts/inside/operation-achilles.mp3/view
- Another superb source of information is the so-called "Castleman Affidavit"--
- this affidavit was used to justify the arrest of group member Daniel Castleman.
- The Castleman affidavit explains the group's methodology (or modus operandi)
- in detail.
- It can be seen at: http://www.rep-am.com/newsdocuments/affidavit.pdf
- Another good source of information is:
- http://www.policyb.org/downloads/Operation_Achilles.pdf
- Depending on which affidavit you believe, only about 1/3 to 1/2 of the
- alleged members of this pedophile ring were ever identified and apprehended.
- As I said earlier, the alleged leader of this ring used the nic "Yardbird".
- Yardbird made a re-appearance on Usenet in both 2009 and 2010 on the date
- corresponding to the first and second anniversaries of the busts in 2008.
- His intent was to show that he was still free, and to answer people's
- questions.
- One of the most important things Yardbird stated were that everyone in the
- group who used Tor and remailers remained free, while those who relied on
- services such as Privacy.LI were arrested and convicted.
- Yardbird further commented that several members of the group, including his
- second-in-command Christopher Stubbings (Helen) and Gary Lakey (Eggplant)
- were Privacy.LI users -- in fact he stated that they used it for everything.
- (Helen is currently serving a 25-year sentence in the UK, while Eggplant is
- serving life in an Arizona prison.)
- Eggplant literally became notorious because of his constant promotion of
- Privacy.LI -- he continually boasted that he could not be caught because
- Privacy.LI did not keep logs, and they were located outside of U.S.
- jurisdiction.
- I pointed out to anyone who would listen that services such as Privacy.LI
- were for /privacy/ -- not for anonymity. In an ideal situation, one needs
- both to be private as well as anonymous. Essentially, what Privacy.LI
- supplied was a type of VPN service, providing an encrypted tunnel for data
- to travel between two endpoints--the customer's computer being one endpoint,
- while the Privacy.LI servers provided the other. While there was a degree of
- privacy, there was NO anonymity at all--so it really didn't come as a
- surprise that Privacy.LI's customers were among those arrested. It is also
- worthy of note that Privacy.LI earned a 2005 entry in cryptographer Bruce
- Schneier's "doghouse" as I pointed out more than once.
- See: http://www.schneier.com/blog/archives/2005/07/the_doghouse_pr.html
- As I pointed out repeatedly, NO service operator is going to go to prison to
- protect the identity of his customers -- every last one of them will roll
- over on you, if given the opportunity.
- You might ask, "How was the existence of 'the group' discovered?"
- Simple. Through one of the oldest investigative techniques of all -- the
- informer. The Australian police arrested a man on totally unrelated child
- pornography charges -- presumably as part of a plea deal, he revealed the
- existence of 'the group' and handed over a PGP public/private keypair and
- password.
- Now, it is worthy of note that the Department of Internal Affairs of New
- Zealand had earlier informed the Australian police of the existence of PGP-
- encrypted traffic in a number of Usenet newsgroups.
- These messages, from users with handles like "Big Block" and Subject: lines
- like "New Car Contracts" were rather odd, to say the least. I also noticed
- some of these--it was quite clear that there were a group of people
- communicating in private, but obviously there was no way to determine /who/
- was communicating, or /what/ they were communicating about.
- If the Australian police had not had a lucky break, by arresting one of the
- members of the group on totally unrelated child pornography charges, they
- would, in all likelihood, /still/ be in the dark about what was going on.
- Having acquired from the informer the current group PGP public/private
- keypair, and its passphrase meant that the police could assume this group
- member's identity, and furthermore, read all the encrypted traffic posted by
- members of the group.
- So it was that Constable Brenden Power of the Queensland Police Service used
- this assumed identity from August 31, 2006 through December 15, 2007.
- Constable Power spent almost 18 months working out of FBI HQ in Washington,
- DC while working on this case.
- In many ways, this case was unprecedented. No similar pedophile ring had
- ever previously employed the types of security measures that this group did;
- also unprecedented was the information provided by the informant, who gave
- the police the tools needed to infiltrate the group--without the informant's
- help, they could _never_ have succeeded.
- Once the group was penetrated, the police were able to take advantage of a
- few factors:
- 1) They had the informant's computer, with all its email, PGP keys and the
- like. This provided a history, which made it easier to continue the
- impersonation.
- 2) By the time it was penetrated, the group had been operating for about 5
- years. By this time, the group had jelled into a community -- people were
- familiar with each other, they often let their guards down, and would
- sometimes reveal tidbits of personal information. This is especially the
- case when they thought their messages were secure, and beyond the ability
- of the police to intercept--they would say things that they would *never*
- say in the open.
- So, as you can see, the group was pretty much an of open book to the police;
- they were completely and thoroughly penetrated. Despite that, however, the
- majority of the group were _still_ able to remain at large, and were neither
- positively identified nor arrested.
- This is due to the privacy tools (i.e. tor, nymservers, remailers) that were
- employed. Even with everything else being an open book, those using these
- tools still managed to elude capture.
- By now, you're probably thinking, "Why is he going on about pedophiles?"
- "Pedophiles are disgusting! They should all be shot!"
- Leaving aside my personal feelings about pedophiles, I brought up this case
- as an example for several reasons:
- 1) Child pornography is a serious crime in virtually every jurisdiction.
- As this example demonstrates, police will work together, even across
- national boundaries, to investigate these crimes. They are willing
- to invest considerable time, manpower and money in pursuit of these
- suspects. The only other crimes which usually merit this type of
- approach are drug/gun-running or terrorism. The level of effort
- expended in pursuing this group can be seen in that even FBI
- executive assistant director J. Stephen Tidwell was involved.
- Normally one would not expect FBI personnel that highly placed
- to be involved -- this shows the level of importance placed on
- this particular investigation. (A year or so after the busts,
- Yardbird himself expressed astonishment that the FBI would
- consider his group such a priority.)
- 2) This case is the only one that I'm aware of, where suspects were
- using sophisticated tools like PGP, Tor, anonymous remailers and
- nymservers.
- 3) This case underscores the effectiveness of these tools even against
- well-funded, powerful opponents like the FBI, Europol, and Interpol.
- (N.B.: FWIW, those who were caught used either inappropriate and/or
- ineffective tools and techniques to protect themselves.
- 4) I fully understand most people's disgust at the types of crimes/
- criminals being discussed here. That said, it is important to
- remember that one simply cannot design a system that provides
- protection for one class of people, but denies it for another.
- You can't, for example, deploy a system that provides privacy/
- anonymity for political dissidents, or whistle blowers, and yet
- denies it to pedophiles -- either *everyone* is safe, or NO ONE
- is safe. This may not be palatable, but these are the facts.
- Final Thoughts
- ==============
- While this case shows the strengths of the current technologies, it
- nevertheless underscores that the human element cannot be disregarded. It
- must continually be borne in mind that the weakest element in /any/ security
- system is the human element. This has been true since before Sun Tzu wrote
- his immortal treatise, The Art of War about 2500 years ago. It is, in fact,
- for this reason that Sun Tzu is still studied in military academies to this
- very day. It is not for nothing that Sun Tzu devoted an entire chapter in
- his seminal work to the use of spies.
- As we have seen, infiltration is still a highly effective tactic. The group
- was particularly susceptible to this, as the members were unknown to each
- other, by deliberate design. If someone were to be apprehended, they could
- be forced to turn over PGP private keys, passphrases, etc. These can then be
- used by the authorities to PGP-sign messages, which normally would be taken
- as proof that the messages in question are genuine and untampered-with. This
- is likely what happened in the case of the group.
- Traditionally, espionage cells have been made up of only a handful of persons,
- each known to the other -- the idea behind this was to limit the damage in
- the case of the cell being either penetrated or exposed.
- The only types of organizations that cannot be penetrated by the authorities
- are those close-knit, bound by blood or other kinship ties. The only possible
- recourse for the authorities in these cases is to try to turn someone on the
- inside against his fellows.
- Baal <Baal@nym.mixmin.net>
- PGP Key: http://wwwkeys.pgp.net:11371/pks/lookup?op=get&search=0x1E92C0E8
- PGP Key Fingerprint: 40E4 E9BB D084 22D5 3DE9 66B8 08E3 638C 1E92 C0E8
- Retired Lecturer, Encryption and Data Security, Pedo U, Usenet Campus
- - --
- Sed quis custodiet ipsos Custodes?" -- "Who will watch the Watchmen?"
- -- Juvenal, Satires, VI, 347. circa 128 AD
- If you accept that freedom of speech is important, then you are going to
- have to defend the indefensible. -- Neil Gaiman
- He that would make his own liberty secure must guard even his enemy from
- oppression.
- -- Thomas Paine
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