Schneier - The Evolution of Darknets

This is interesting:

To prevent the problems of customer binding, and losing business when darknet markets go down, merchants have begun to leave the specialized and centralized platforms and instead ventured to use widely accessible technology to build their own communications and operational back-ends.

Instead of using websites on the darknet, merchants are now operating invite-only channels on widely available mobile messaging systems like Telegram. This allows the merchant to control the reach of their communication better and be less vulnerable to system take-downs. To further stabilize the connection between merchant and customer, repeat customers are given unique messaging contacts that are independent of shared channels and thus even less likely to be found and taken down. Channels are often operated by automated bots that allow customers to inquire about offers and initiate the purchase, often even allowing a fully bot-driven experience without human intervention on the merchant's side.

[...]

The other major change is the use of "dead drops" instead of the postal system which has proven vulnerable to tracking and interception. Now, goods are hidden in publicly accessible places like parks and the location is given to the customer on purchase. The customer then goes to the location and picks up the goods. This means that delivery becomes asynchronous for the merchant, he can hide a lot of product in different locations for future, not yet known, purchases. For the client the time to delivery is significantly shorter than waiting for a letter or parcel shipped by traditional means - he has the product in his hands in a matter of hours instead of days. Furthermore this method does not require for the customer to give any personally identifiable information to the merchant, which in turn doesn't have to safeguard it anymore. Less data means less risk for everyone.

The use of dead drops also significantly reduces the risk of the merchant to be discovered by tracking within the postal system. He does not have to visit any easily to surveil post office or letter box, instead the whole public space becomes his hiding territory.

Cryptocurrencies are still the main means of payment, but due to the higher customer-binding, and vetting process by the merchant, escrows are seldom employed. Usually only multi-party transactions between customer and merchant are established, and often not even that.

[...]

Other than allowing much more secure and efficient business for both sides of the transaction, this has also lead to changes in the organizational structure of merchants:

Instead of the flat hierarchies witnessed with darknet markets, merchants today employ hierarchical structures again. These consist of procurement layer, sales layer, and distribution layer. The people constituting each layer usually do not know the identity of the higher layers nor are ever in personal contact with them. All interaction is digital -- messaging systems and cryptocurrencies again, product moves only through dead drops.

The procurement layer purchases product wholesale and smuggles it into the region. It is then sold for cryptocurrency to select people that operate the sales layer. After that transaction the risks of both procurement and sales layer are isolated.

The sales layer divides the product into smaller units and gives the location of those dead drops to the distribution layer. The distribution layer then divides the product again and places typical sales quantities into new dead drops. The location of these dead drops is communicated to the sales layer which then sells these locations to the customers through messaging systems.

To prevent theft by the distribution layer, the sales layer randomly tests dead drops by tasking different members of the distribution layer with picking up product from a dead drop and hiding it somewhere else, after verification of the contents. Usually each unit of product is tagged with a piece of paper containing a unique secret word which is used to prove to the sales layer that a dead drop was found. Members of the distribution layer have to post security - in the form of cryptocurrency - to the sales layer, and they lose part of that security with every dead drop that fails the testing, and with every dead drop they failed to test. So far, no reports of using violence to ensure performance of members of these structures has become known.

This concept of using messaging, cryptocurrency and dead drops even within the merchant structure allows for the members within each layer being completely isolated from each other, and not knowing anything about higher layers at all. There is no trace to follow if a distribution layer member is captured while servicing a dead drop. He will often not even be distinguishable from a regular customer. This makes these structures extremely secure against infiltration, takeover and capture. They are inherently resilient.

[...]

It is because of the use of dead drops and hierarchical structures that we call this kind of organization a Dropgang.

from Schneier on Security https://www.schneier.com/blog/archives/2019/01/the_evolution_o.html