The Talking Drum as a Communication Channel

We just wrapped up Week 1 of my UIUC course, ECE598DA: Topics in Information-Theoretic Cryptography. The class introduces students to how tools from information theory can be used to design and analyze both privacy applications and foundational cryptographic protocols. Like many courses in privacy and security, we began with the classic one-time pad as our entry point into the fascinating world of secure communication.

We also explored another ‘tool’ for communication: the talking drum. This musical tradition offers a striking example of how information can be encoded, transmitted, and understood only by those familiar with the underlying code. In class, I played a video of a master drummer to bring this idea to life.

What Are Talking Drums?

Talking drums, especially those like the Yoruba dùndún, are traditional African hourglass‑shaped percussion instruments prized for their ability to mimic speech. Skilled drummers can vary pitch and rhythm to convey tonal patterns, effectively transmitting messages over short distances.

  • Speech surrogacy: The drum replicates the microstructure of tonal languages by adjusting pitch and rhythm, embodying what researchers call a “speech surrogate” .
  • Cultural ingenuity: Historically, these drums served as everyday communication tools, not merely for music or rituals but for sharing proverbs, announcements, secure messages, and more.

Here’s one of the exercises I gave students in Week 1:

Exercise: Talking drums. Chapter 1 of Gleick’s The Information highlights the talking drum as an early information technology: a medium that compresses, encodes, and transmits messages across distance. Through a communications theory lens, can you describe the talking drum as a medium that achieves a form of secure communication?

And here’s a possible solution:

African talking drums (e.g., Yoruba “dùndún”) reproduce the pitch contours and tonal patterns of speech. Since many West African languages are tonal, the drum reproduces structure without literal words.

  • Encoding: A spoken sentence is mapped into rhythmic and tonal patterns.
  • Compression: The drum strips away vowels and consonants, leaving tonal “skeletons.”
  • Security implication: To an outsider unfamiliar with the tonal code or local idioms, the message is incomprehensible. In effect, the drum acts as an encryption device where the key is cultural and linguistic context.

There are a few entities to model:

  • Source: Message in natural language (tonal West African language, e.g., Yoruba).
  • Encoder: Drummer maps source to a drummed signal using tonal contours and rhythmic patterns.
  • Channel: Physical propagation of drum beats across distance, subject to noise (wind, echo, competing sounds).
  • Legitimate receiver: Villager fluent in both the spoken language and cultural conventions.
  • Adversary: Outsider (colonial administrator, rival tribe, foreign merchant) who hears the same signal but lacks full knowledge of mapping or redundancy rules.

Let X denote a message in a tonal language (e.g., Yoruba). A drummer acts as an encoder E mapping X to a drummed signal S = E(X,K), where K denotes shared cultural/linguistic knowledge (idioms, proverbs, discourse templates) known to legitimate receivers but not to outsiders. The signal S traverses a physical channel C and is received as Y_R by insiders and as Y_A by an adversary (outsider). Decoders D_R and D_A attempt to reconstruct X:

NaijaCoder at the University of Lagos (UNILAG)

Last year, NaijaCoder started hosting its Lagos camp at the University of Lagos (UNILAG). The Abuja camp started in 2022.

The University of Lagos (UNILAG) is a leading public research university in Lagos, Nigeria. It is often celebrated as “the University of First Choice and the Nation’s Pride.” Founded in 1962, UNILAG was established shortly after Nigeria’s independence as one of the country’s first generation universities. Over the past six decades, it has grown into one of Nigeria’s most prestigious institutions. I’ll briefly discuss UNILAG’s rich history and highlight recent NaijaCoder camps at UNILAG’s Artificial Intelligence and Robotics Lab (AirLab). The goal of this post is not to provide a comprehensive overview of UNILAG but to highlight NaijaCoder’s connections to the university.

A Brief History of UNILAG

UNILAG was established by an Act of Parliament in 1962 as an immediate response to the national need for a competent professional workforce to drive Nigeria’s social, economic, and political development. (At the time, I believe the Federal Capital Territory of Nigeria was still Lagos.) UNILAG opened its doors on October 22, 1962, starting with just 131 students, but rapidly expanded in scope and enrollment. By 1964, additional faculties such as Arts, Education, Engineering, and Science had been added to the original three faculties (Business & Social Studies, Law, and Medicine). This early growth set the stage for UNILAG’s transformation into a comprehensive university. Today, the university enrolls tens of thousands of students and operates across three campuses in Lagos: the main campus at Akoka in Yaba, the College of Medicine at Idi-Araba, and a smaller campus at Yaba for radiography. (I’m currently writing this post at the Akoka campus.)

From its inception, UNILAG played a critical role in Nigeria’s development. During the decades when Lagos was the nation’s capital, the university became a key intellectual hub influencing politics and public policy. Its student body was notably diverse and cosmopolitan, attracting talent from different regions and economic backgrounds, which helped cultivate a generation of educated Nigerians poised to lead in various sectors. Over the years, UNILAG has weathered challenges, such as economic downturns in the 1980s that strained facilities and led to some brain drain, but it rebounded by expanding revenue streams, improving its academic reputation, and drawing in more students. By 2011, enrollment had grown to over 39,000, a far cry from the 131 pioneer students in 1962. In recent times, student population figures have exceeded 57,000 annually, reflecting UNILAG’s status as one of Nigeria’s largest and most in-demand universities. In fact, it is one of the country’s most competitive schools for admissions.

University leadership has made it clear that research and innovation are at the heart of UNILAG’s future trajectory. Professor Folasade Ogunsola, who became UNILAG’s first female Vice-Chancellor in 2022, has articulated a vision to make UNILAG a “future-ready, research-oriented and enterprise-driven hub.” She introduced a strategic framework with the acronym “FIRM” – focusing on Financial re-engineering, Infrastructural development, Reputation building through teaching/research/innovation, and Manpower development. A major part of this vision, it seems, is strengthening research output and global partnerships (through initiatives like NaijaCoder partnerships).

NaijaCoder Camps at UNILAG AIRLab (2024 & 2025) – Empowering the Next Generation

NaijaCoder is a non-profit organization dedicated to teaching algorithms to young Nigerians. In the summers of 2024 and 2025, UNILAG’s AIRLab (AI and Robotics Lab) partnered with NaijaCoder to run intensive camps in Lagos. Prof. Chika Yinka-Banjo is the director of the AIRLab; she has been instrumental in bringing the program to Lagos, from initial recruiting to daily daily logistics to TA recruitment.

In Summer 2024, the Lagos NaijaCoder camp was held right on UNILAG’s campus in collaboration with the AIRLab. For 14 days, about 50 students (mostly teens) immersed themselves in learning the basics of algorithms at the UNILAG AI & Robotics Lab. The curriculum introduced the participants to core concepts in an accessible way. The camp instructors covered everything from basic Python programming syntax and data types, to loops and recursion, searching and sorting algorithms, basic data structures, and use of python libraries. By the final days, students were applying their knowledge to solve problems and took an exam/competition to cap off their learning. The hands-on sessions were facilitated by instructors from NaijaCoder alongside UNILAG volunteers. Following the success of the 2024 program, we just finished Week 1 of NaijaCoder at the UNILAG AIRLab this summer (Summer 2025).

At NaijaCoder, we look forward to continued collaboration with UNILAG to bring computing-related curricula to classrooms across Nigeria.

A Tutorial on Secure Data Markets

tl;dr We’re hosting a tutorial at SIGMOD 2025 in Berlin on Privacy and Security in Distributed Data Markets. Come join us!

The Origins: From ChatGPT to Data Markets

It’s 2022, and ChatGPT has just exploded onto the scene. A few weeks later, I found myself asking a simple question: What is the value of the data used to train these powerful language models?

Obviously, I’m not the first person to ask that question but it led me to explore a few topics related to the question. At the time, Eugene Wu pointed me toward a growing thread in the database community: data markets, which are structured platforms where data can be bought, sold, and exchanged just like goods or services. I soon discovered that data markets are a key research direction for Raul Castro Fernandez and others, especially as data becomes one of the most valuable digital commodities.

What good is a data market if the very act of exchanging data opens both sellers and buyers up to liability? If transactions in the market result in devastating privacy breaches, who’s going to participate? The stakes are not hypothetical. Consider:

  • In June 2025, the UK fined DNA testing firm 23andMe £18 million ($23 million) for failing to prevent a massive 2023 data breach that exposed the genetic information of millions. (The Guardian)
  • Recently, Texas forced Google to pay $1.38 billion in a major privacy case—showing that Big Tech is not above the law when it comes to misusing user data. (Times of India)

Privacy and security are not just afterthoughts. They are prerequisites for data markets to thrive.

The Research Front: From Theory to Practice

The good news is that the academic community is rising to this challenge. At Columbia University, Zach Huang’s thesis work has focused on designing private data markets, aiming to ensure data utility while enforcing strong privacy guarantees. Meanwhile, Jiaxiang Liu has been exploring causal search systems and thinking hard about how they might be extended to enforce privacy and auditability by design.

These lines of work highlight a crucial pivot in how we should think about data ecosystems: not only what is exchanged, but how it is protected, tracked, and regulated.

Come Learn With Us: SIGMOD 2025 Tutorial

That’s why we’re organizing a tutorial at SIGMOD 2025 in Berlin, focusing on the intersection of privacy, security, and data markets. We believe that privacy-preserving and secure systems must be core to the infrastructure of data marketplaces (and not just bolted on afterward!).

The tutorial is split into five parts:

Part I: Survey on Data Markets

An overview of recent work on data valuation, pricing mechanisms, data provenance, and marketplace design. We’ll survey both academic systems and real-world platforms.

Part II: Privacy and Security Risks

We’ll walk through concrete case studies of real-world privacy failures in data markets (including, perhaps, those mentioned above), and examine the technical and legal gaps that led to them.

Part III: Privacy-Preserving Technologies and Security Tools

We will explore cutting-edge tools that can enforce privacy and security in data transactions:

  • Differential privacy
  • Secure multiparty computation
  • Federated learning

Part IV: Regulatory Considerations

A guided discussion on the legal frameworks that govern data usage (e.g., GDPR, Title 13), recent enforcement actions, and what upcoming regulations might mean for data markets.

Part V: Open Problems & Future Directions

We’ll close with an interactive session on open research questions:

  • How do we balance utility and privacy in high-value data?
  • Can we build incentive-compatible marketplaces that respect user rights?
  • What new threats will arise in markets built on AI-generated data?

Why This Matters

As AI systems become more powerful, the value (and vulnerability) of data becomes ever more pronounced. If we want a future where data can be shared, monetized, and reused responsibly, we must take privacy and security seriously.

Whether you’re a researcher, practitioner, policymaker, or simply curious about the future of data, we hope you’ll join us for this tutorial at SIGMOD 2025.

👉 See you in Berlin!