Welcome to an alley of the Internet!

I’m Milo Trujillo, a computer and social scientist, activist, and hacker.

Blog posts cover a myriad of technical and social topics, often focused on security and organizing resistance.


Hacker Community Espionage

I recently got to see a talk at the Chaos Communication Congress titled “When the Dutch secret service knocks on your door”, with the following description:

This is a story of when the Dutch secret service knocked on my door just after OHM2013, what some of the events that lead up to this, our guesses on why they did this and how to create an environment where we can talk about these things instead of keeping silent.

Since the talk was not recorded, the following is my synopsis and thoughts. This post was written about a week after the talk, so some facts may be distorted by poor memory recall.

  • The speaker was approached by members of the Dutch secret service at his parents’ house. They initially identified themselves as members of the department of the interior, but when asked whether they were part of the secret service, they capitulated.

  • The agents began by offering all-expenses-paid travel to any hackathon or hackerspace. All the speaker needed to do was write a report about their experience and send it back. A relatively harmless act, but it means they would be an unannounced informant in hacker communities.

  • When the author refused, the agents switched to harder recruitment techniques. They pursued the author at the gym, sat nearby in cafes when the author held meetings for nonprofits, and likely deployed an IMSI catcher to track them at a conference.

  • Eventually, the author got in contact with other members of the hacker community that had also been approached. Some of them went further through the recruitment process. The offers grew, including “attend our secret hacker summer camp, we’ll let you play with toys you’ve never heard of,” and “If you want to hack anything we can make sure the police never find out.” In either of these cases the recruit is further indebted to the secret service, either by signing NDAs or similar legal commitments to protect government secrets, or by direct threat, wherein the government can restore the recruit’s disappeared criminal charges at any time.

I have two chief concerns about this. First, given how blatant the secret service was in their recruitment attempts, and that we only heard about their attempts in December of 2017, we can safely assume many people accepted the government’s offer. Therefore, there are likely many informants working for the secret service already.

Second, this talk was about the Netherlands - a relatively small country not known for their excessive surveillance regimes like the Five Eyes. If the Netherlands has a large group of informants spying on hackerspaces and conferences around the globe, then many other countries will as well, not to mention more extreme measures likely taken by countries with more resources.

From this, we can conclude there are likely informants in every talk at significant conferences. Every hackerspace with more than token attendance is monitored. This is not unprecedented - the FBI had a vast array of informants during the COINTELPRO era that infiltrated leftist movements throughout the United States (along with much less savory groups like the KKK), and since shortly after 9/11 has used a large group of Muslim informants to search for would-be terrorists.

Posted 1/7/18


Alcoholics Anonymous as Decentralized Architecture

Most examples of decentralized organization are contemporary: Black Lives Matter, Antifa, the Alt-Right, and other movements developed largely on social media. Older examples of social decentralization tend to be failures: Collapsed Hippie communes of the 60s, anarchist and communist movements that quickly collapsed or devolved to authoritarianism, the “self-balancing free market,” and so on.

But not all leaderless movements are short-lived failures. One excellent example is Alcoholics Anonymous: An 82-year-old mutual aid institution dedicated to helping alcoholics stay sober. Aside from their age, AA is a good subject for study because they’ve engaged in a great deal of self-analysis, and have very explicitly documented their organizational practices.

Let’s examine AA’s Twelve Traditions and see what can be generalized to other organizations. The twelve traditions are reproduced below:

  1. Our common welfare should come first; personal recovery depends on AA unity.

  2. For our group purpose there is but one ultimate authority - a loving God as He may express Himself in our group conscience.

  3. The only requirement for AA membership is a desire to stop drinking.

  4. Each group should be autonomous except in matters affecting other groups or AA as a whole.

  5. Each group has but one primary purpose - to carry its message to the alcoholic who still suffers.

  6. An AA group ought never endorse, finance or lend the AA name to any related facility or outside enterprise, lest problems of money, property and prestige divert us from our primary purpose.

  7. Every AA group ought to be fully self-supporting, declining outside contributions.

  8. Alcoholics Anonymous should remain forever nonprofessional, but our service centers may employ special workers.

  9. AA, as such, ought never be organized; but we may create service boards or committees directly responsible to those they serve

  10. Alcoholics Anonymous has no opinion on outside issues; hence the AA name ought never be drawn into public controversy.

  11. Our public relations policy is based on attraction rather than promotion; we need always maintain personal anonymity at the level of press, radio and films.

  12. Anonymity is the spritual foundation of all our traditions, ever reminding us to place principles before personalitites.

The above twelve rules can be distilled to three themes:

  • The group comes first

  • The group is single-issue

  • The group should be independent of any external or internal structures

The first theme stresses anonymity in an interesting way: Not to protect individual members (many of whom want to be anonymous when in an organization like AA), but to prevent the rise of “rock-stars”, or powerful individuals with celebrity status. Personal power is prone to abuse, both at an inter-personal level (see the plethora of sexual abuse cases in the news right now), and at a structural level, where the organization becomes dependent on this single individual, and is drawn in to any conflict surrounding the celebrity.

The solution to a rock-star is to kick them out of the organization, and maintain a healthier community without them. AA has gone a step further however, and outlines how to prevent the rise of a rock-star by preventing any personal identification when communicating to the outside world. When you are speaking to the press you are Alcoholics Anonymous, and may not use your name. For further discussion on rock-stars in tech communities, see this article.

The single-issue design is an unusual choice. Many social movements like the Black Panthers stress solidarity, the idea that we should unite many movements to increase participants and pool resources. This is the same principle behind a general strike, and broad, cross-issue activist networks like the Indivisible movement. However, focusing on a single issue continues the trend of resisting corruption and abuse of power. AA keeps a very strict, simple mission, with no deviations.

The last theme, total organizational independence, is also unusual. Organizations that fear external attack, like terrorist cells, may operate in isolation from other cells with little to no higher-level coordination. Organizations avoiding internal corruption, like the Occupy movement, or fraternities, may limit internal leadership and centralization of power using systems like Robert’s Rules of Order or Clusters & Spokes Councils, or they may organize more anarchically, through organic discussion on social media. Avoiding both internal and external hierarchy, however, sacrifices both large-scale coordination and quick decision making. This works for Alcoholics Anonymous, because their mission is predefined and doesn’t require a great deal of complex leadership and decision making. It is also used by Antifa, where local groups have no contact with one another and rely on collective sentiment to decide on actions.

Overall, AA is an interesting introduction to decentralized organizations. I will revisit these ideas as I learn more.

Posted 1/6/18


Halftone QR Codes

I recently encountered a very neat encoding technique for embedding images into Quick Response Codes, like so:

Halftone QR Code Example

A full research paper on the topic can be found here, but the core of the algorithm is actually very simple:

  1. Generate the QR code with the data you want

  2. Dither the image you want to embed, creating a black and white approximation at the appropriate size

  3. Triple the size of the QR code, such that each QR block is now represented by a grid of 9 pixels

  4. Set the 9 pixels to values from the dithered image

  5. Set the middle of the 9 pixels to whatever the color of the QR block was supposed to be

  6. Redraw the required control blocks on top in full detail, to make sure scanners identify the presence of the code

That’s it! Setting the middle pixel of each cluster of 9 generally lets QR readers get the correct value for the block, and gives you 8 pixels to represent an image with. Occasionally a block will be misread, but the QR standard includes lots of redundant checksumming blocks to repair damage automatically, so the correct data will almost always be recoverable.

There is a reference implementation in JavaScript of the algorithm I’ve described. I have extended that code so that when a pixel on the original image is transparent the corresponding pixel of the final image is filled in with QR block data instead of dither data. The result is that the original QR code “bleeds in” to any space unused by the image, so you get this:

Halftone QR with background bleed

Instead of this:

Halftone QR without background bleed

This both makes the code scan more reliably and makes it more visually apparent to a casual observer that they are looking at a QR code.

The original researchers take this approach several steps further, and repeatedly perturb the dithered image to get a result that both looks better and scans more reliably. They also create an “importance matrix” to help determine which features of the image are most critical and should be prioritized in the QR rendering. Their code can be found here, but be warned that it’s a mess of C++ with Boost written for Microsoft’s Visual Studio on Windows, and I haven’t gotten it running. While their enhancements yield a marked improvement in image quality, I wish to forgo the tremendous complexity increase necessarily to implement them.

Posted 12/19/17


Cooperative Censorship

I have long been an opponent of censorship by any authority. Suppression of ideas stifles discussion, and supports corruption, authoritarianism, and antiquated, bigoted ideas. I have put a lot of thought in to distributed systems, like Tor or FreeNet, that circumvent censorship, or make it possible to host content that cannot be censored.

However, the recent Charlottesville protests show another side of the issue. Giving the alt-right a prolific voice online and in our media has allowed the Nazi ideology to flourish. This isn’t about spreading well-reasoned ideas or holding educational discussion - the goal of white supremacists is to share a message of racial superiority and discrimination based wholly in old hateful prejudice, not science or intellectual debate.

The progress of different hosting providers shutting down the Daily Stormer neo-Nazi community site shows how hesitant Corporate America is to censor - whether out of concern for bad PR, loss of revenue, perception of being responsible for the content they facilitate distribution of, or (less likely) an ideological opposition to censorship.

Ultimately, I still belief in the superiority of decentralized systems. Money-driven corporations like GoDaddy and Cloudflare should not be in the position where they are cultural gatekeepers that decide what content is acceptable and what is not. At the same time, a distributed system that prevents censorship entirely may provide an unreasonably accessible platform for hate speech. No censorship is preferable to authoritarian censorship, but is there a way to build distributed community censorship, where widespread rejection of content like white supremacy can stop its spread, without allowing easy abuse of power? If it is not designed carefully such a system would be prone to Tyranny of the Majority, where any minority groups or interests can be oppressed by the majority. Worse yet, a poorly designed system may allow a large number of bots to “sway the majority”, effectively returning to an oligarchic “tyranny of the minority with power” model. But before ruling the concept out, let’s explore the possibility some…

Existing “Distributed Censorship” Models

Decentralized Twitter clone Mastadon takes a multiple-instances approach to censorship. Effectively, each Mastadon server is linked together, or “federated”, but can refuse to federate with particular servers if the server admin chooses to. Each server then has its own content guidelines - maybe one server allows pornography, while another server forbids pornography and will not distribute posts from servers that do. This allows for evasion of censorship and the creation of communities around any subject, but content from those communities will not spread far without support from other servers.

Facebook lookalike Diaspora has a similar design, distributing across many independently operated servers called “pods”. However, content distribution is primarily decided by the user, not the pod administrator. While the pod administrator chooses what other pods to link to, the user independently chooses which users in those pods their posts will be sent to, with a feature called “aspects”. This ideally lets a user segment their friend groups from family or work colleagues, all within the same account, although there is nothing preventing users from registering separate accounts to achieve the same goal.

Both of these models distribute censorship power to server administrators, similar to forum or subreddit moderators. This is a step in the right direction from corporate control, but still creates power inequality between the relatively few server operators and the multitude of users. In the Mastadon example, the Mastadon Monitoring Project estimates that there are about 2400 servers, and 1.5 million registered users. That is, about 0.16% of the population have censorship control. While there’s nothing technical stopping a user from starting their own server and joining the 0.16%, it does require a higher expertise level, a server to run the software on, and a higher time commitment. This necessarily precludes most users from participating in censorship (and if we had 1.5 million Mastadon servers then administering censorship would be unwieldy).

Other Researcher’s Thoughts

The Digital Currency Initiative and the Center for Civic Media (both MIT groups) released a relevant report recently on decentralized web technologies, their benefits regarding censorship, and adoption problems the technologies face. While the report does not address the desirability of censoring hate speech, it does bring up the interesting point that content selection algorithms (like the code that decides what to show on your Twitter or Facebook news feeds) are as important to censorship as actual control of what posts are blocked. This presents something further to think about - is there a way to place more of the selection algorithm under user control without loading them down with technical complexity? This would allow for automatic but democratic censorship, that may alleviate the disproportionate power structures described above.

Posted 8/19/17


Braess’s Paradox

I had the great fortune of seeing a talk by Brian Hayes on Braess’s Paradox, an interesting network congestion phenomenon. In this post I’ll talk about the problem, and some ramifications for other fields.

The Problem

Consider a network of four roads. Two roads are extremely wide, and are effectively uncongested, regardless of how many cars are present. They still have speed limits, so we’ll say there’s a constant traversal time of “one hour” for these roads. The other two roads, while more direct and thereby faster, have only a few lanes, and are extremely prone to congestion. As an estimate, we’ll say the speed it takes to traverse these roads scales linearly with “N”, the number of cars on the road, such that if all the cars are one one road it will take one hour to travel on.

Plain Network

If a driver wants to get from point A to point B, what route is fastest? Clearly, by symmetry, the two paths are the same length. Therefore, the driver should take whatever path is less-congested, or select randomly if congestion is equal. Since half the cars will be on each path, the total commute time is about 1.5 hours for all drivers.

However, consider the following change:

Magic Shortcut Network

In this network we’ve added a new path that’s extremely fast (no speed limits, because they believe in freedom), to the point that we’ll consider it instantaneous.

What is the optimal path for a driver now? A lone driver will obviously take the first direct road, then the shortcut, then the second direct road. However, if all “N” drivers take this route the small roads will be overloaded, increasing their travel time to one hour each. The total commute for each driver will now be two hours.

Consider that you are about to start driving, and the roads are overloaded. If you take the short route your commute will be two hours long. However, if you take the long route your commute will be two hours long, and the other roads will be less overloaded (since without you only N-1 cars are taking the route), so everyone else will have a commute slightly shorter than two hours. This means from a greedy algorithm perspective there is always an incentive to take the more direct route, and help perpetuate the traffic problem.

Simply put, adding a shortcut to the network made performance worse, not better.

The Solution

There are a number of potential solutions to the problem. Law enforcement might demand that drivers select their routes randomly, saving everyone half an hour of commute. Similarly, self-driving cars may enforce random path selection, improving performance without draconian-feeling laws. These are both “greater good” solutions, which assume drivers’ willingness to sacrifice their own best interests for the interests of the group. Either of these solutions provide an incentive for drivers to cheat - after all, the shortcut is faster so long as there are only a few people using it.

Another option is limiting information access. The entire problem hinges on the assumption that users know the to-the-moment traffic information for each possible route, and plan their travel accordingly. Restricting user information to only warn about extreme congestion or traffic accidents effectively prohibits gaming the system, and forces random path selection.

Generalization

Braess’s Paradox is an interesting problem where providing more limited information improves performance for all users. Are there parallels in other software problems? Any system where all nodes are controlled by the same entity can be configured for the “greater good” solution, but what about distributed models like torrenting, where nodes are controlled by many people?

In a torrenting system, users have an incentive to “cheat” by downloading chunks of files without doing their share and uploading in return. Consider changing the system so users do not know who has the chunks they need, and must made trades with various other nodes to acquire chunks, discovering after the fact whether it was what they were looking for. Users now must participate in order to acquire the data they want. This may slow the acquisition of data, since you can no longer request specific chunks, but it may also improve the total performance of the system, since there will be far more seeders uploading data fragments.

The performance detriment could even be alleviated by allowing the user to request X different chunks in their trade, and the other end must return the appropriate chunks if they have them. This limits wasteful exchanges, while still ensuring there are no leechers.

Fun thought experiment that I expect has many more applications.

Posted 8/8/17


View older posts