Blockchain Could Answer Contact Tracing Privacy Concerns

By Zach Brumbelow, Robert Mis and Anastis Anastasiou

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Law360 (September 4, 2020, 12:17 PM EDT) —

Zach Brumbelow
Robert Mis
Anastis Anastasiou

COVID-19 continues to present a major threat to our social and economic life. At present, there are no proven vaccines or known cures.

Social distancing and contact tracing are therefore two of the most common approaches that have been used to defend against the threat of the virus. Contact tracing in particular has become prevalent as the initial lockdowns have lifted and people are traveling more and returning to work.

However, there are privacy and security concerns related to contact-tracing implementation. Blockchain technology may provide an effective approach to contact-tracing implementation by ensuring security and privacy of personal data.

Privacy Concerns With Contract Tracing

A potential solution has been outlined by former federal health officials, advising for broad-based testing, contact tracing and isolation of infected individuals.[1] Countries that have successfully implemented these protection measures, such as Vietnam,[2] South Korea[3] and Iceland,[4] for example, have observed substantial containment and reduction in new COVID-19 cases.

Some key challenges in implementing contact-tracing measures include data security, privacy and the handling of sensitive information. Skeptics are raising concerns regarding the acquisition, storing and monitoring of people’s personal health information. Their concerns include issues pertaining to excessive government surveillance, use of data for unintended purposes, as well as data integrity and accuracy.

As contact-tracing techniques often require the collection of private citizen data, addressing such concerns is paramount to successful implementation. Without people’s voluntary consent, the benefits of contact tracing will be limited. An effective approach would require broad participation by the general public and careful, noninvasive monitoring by official government agencies and health organizations.

A notable contact-tracing solution currently under development by a collaboration between Apple Inc. and Google Inc. will allow health authorities to monitor users through smartphone proximity detection.

Two obvious concerns with this solution are privacy and security. Specifically, such technology could potentially allow companies access to personal information, something that can potentially make citizens uncomfortable and less likely to participate in the contact-tracing efforts.

In addition, the proposed solution could be susceptible to malicious activity by actors who can distort data and undermine the tracing system’s effectiveness.

Blockchain’s Answer to Privacy Concerns

A contact-tracing system based on blockchain technology can provide a viable solution by leveraging the core characteristics of blockchain, namely decentralization, confidentiality and immutability. A blockchain-based contact-tracing platform would have a decentralized structure, in which organizations and citizens share and verify information in cryptographic form.

In such a system, the private information would reside with the cryptographic signatures of each citizen. Specifically, each person would own and control his or her private data, allowing him or her to share information with trusted parties only.[5] By establishing a foundation of trust, private citizens, government agencies and health organization can collaborative on a collective contact-tracing effort.

Blockchain technology can provide confidentiality through a zero-knowledge proof, a cryptographic methodology that allows a user to demonstrate that certain information is known, without revealing the information itself. This in effect, allows for the verifiability of information between transacting parties, while the information itself is kept private. Such technological innovation would be extremely useful in a contact-tracing system, where privacy of information is paramount.

By generating and organizing data in a linear and chronological order within a database, blockchain technology provides immutability of information. This means that when a new data point, referred to as a block, is added to the blockchain, it contains a cryptographically embedded reference to a previous block already present in the database. This creates a chain that connects blocks to each other in sequential form. Tampering with a specific block within the blockchain, would require the reworking of all previous blocks connected to it.

The cryptographic linking of information present in the structure of a blockchain thus generates an intertwined network that is almost impossible to corrupt. This unique characteristic of blockchain technology, can provide data integrity and immutability for a contact-tracing solution.

At present, there are several blockchain contact-tracing proposals and projects being developed. Some of the solutions being built are in collaboration with Fortune 100 companies, signifying the heightened interest observed in the application of blockchain technology to contact-tracing efforts.

The solutions are designed to address privacy vulnerabilities, utilize data-verifiability techniques and provide immediate transmission of information to individuals and health authorities. The infographic below illustrates the interconnectivity, data transmission process and layer of security inherent in such blockchain contact-tracing solutions.

Implementation Challenges

A project of this magnitude, nationwide and/or global, would certainly face network bandwidth and scalability issues. Enormous amounts of blockchain addresses, constantly being scanned, verified and updated, would demand enormous computing resources.

Continuously active handheld devices would be susceptible to significant battery drainage and would be required to be always online. While in developed countries these issues may be solvable, they could present serious obstacles in less developed parts of the world.

It should also be noted that less than half of the global population uses a smartphone — 45% in 2020).[6] In the U.S., the factors that most influence smartphone ownership are income level, education and age. For example, while overall sales penetration of smartphones in the U.S. is 79%, it’s 67% among those earning less than $30,000 a year, 57% among high school nongraduates and 46% among people 65 and older.[7]

Finally, given the divisive times in which we live, there will certainly be a significant percentage of individuals who would refuse to participate in the project due to perceived confidentially and privacy issues related to the global governments’ involvement, or mistrust in the intentions of the study.

Looking Into the Future of Blockchain

Blockchain technology has been touted as a solution for many areas that demand privacy, data integrity and security, such as banking, voter identification, logistics, medical record management and asset tokenization, to name a few. Contact tracing is no different, and COVID-19 may bring forth a wave of security-focused blockchain projects that can help protect society and the economy, without foregoing citizen privacy and security.

Zach Brumbelow is a managing director, Robert Mis is a senior director and Anastis Anastasiou is a senior consultant at FTI Consulting Inc.

The opinions expressed are those of the author(s) and do not necessarily reflect the views of the firm, its clients, or Portfolio Media Inc., or any of its or their respective affiliates. This article is for general information purposes and is not intended to be and should not be taken as legal advice.

[1] See:

[2] See:

[3] See:

[4] See:

[5] See:


[7] Ibid.

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