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TraceTogether Data isn't for Criminal Investigation

Below is the original version of my letter, which was published in the Straits Times Forum on Jan 6, 2021, with edits that reduced my emphasis. Highlighted in italics are the changes.

In particular, the published edited version omitted the fact that Function Creep is considered a breach of privacy. It also rephrased my statement that "TT data is useless for criminal investigation" to "TT data may not be that useful for criminal investigation". These edits blunted my arguments.


The recent statement by Minister of State Desmond Tan greatly undermines the repeated assurances given by Minister Vivian Balakrishnan concerning the privacy of TraceTogether (TT) data. The statement revealed that the Singapore Police Force, not just the Ministry of Health, may have access to TT data. This has caused a deep sense of disappointment and resignation in many people, and even betrayal in some.

In the parlance of privacy, using personal data for a purpose other than its original one is called Function Creep, and is a breach of personal privacy. TT data is collected for the purpose of contact tracing only, as originally promised by the government. To use it for criminal investigation, while logical and well-intentioned, constitutes Function Creep, and erodes the trust the government has built up from years of promoting privacy. This erosion is not outweighed by the supposed benefits that TT data brings to criminal investigation.

For one thing, TT data does not add to the repertoire of investigation tools. Surveillance cameras are more effective and efficient for tracking people movement. For another, it is easy to circumvent: a smart criminal can simply turn off Bluetooth and show a fake screenshot of the SafeEntry image. Most SafeEntry sentries will be fooled. Worse, by passing his phone or token to an accomplice, the criminal can create a fake alibi by pretending to be somewhere else other than the crime scene.

In other words, TraceTogether data is useless for criminal investigation. But using it in this manner creates suspicion in the public mind regarding the government's true intention in promoting the TT app and token. I urge the government to reverse its decision, and to ensure that TT data is used solely for contact tracing.


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