Singapore's TraceTogether tokens are the latest efforts to deal with Covid-19 with technology. But they also rekindled a privacy debate.
Wearable devices complement the existing island contact tracking app, to identify people who may have been infected by those who tested positive for the virus.
All users have to do is bring one and the battery lasts up to nine months without needing to be recharged, which one expert said has stunned him.
The government agency that developed the devices recognizes that tokens - and technology in general - are not "a silver bullet", but should increase the efforts of human contact tracers.
The first to receive the devices are thousands of vulnerable seniors who don't own smartphones.
To do this, they had to provide their national ID and phone numbers - users of the TraceTogether app had to start doing the same recently.
If the users of the dongle are positive for the disease, they must deliver their device to the Ministry of Health because - unlike the app - they cannot transmit data on the Internet.
Tracers of human contact will then use the records to identify and recommend others who may have been infected.
"It's very boring in what it does, which is why I think it's good design," says hardware developer Sean Cross.
He was one of four experts invited to inspect one of the devices before they were launched. The group was shown all its components but was not allowed to turn it on.
"It can correlate with who you have been, with whom you have infected and, above all, with who may have infected you," adds Cross.
Help app
Singapore was the first country to deploy a national coronavirus traceability app.
Local authorities say 2.1 million people downloaded the software, representing around 35% of the population.
It is voluntary for everyone except migrant workers who live in dormitories, which account for most of Singapore's over 44,000 infections.
The government says the app has helped quarantine some people faster than would otherwise be possible.
But by its own admission, technology is not working as hoped.
On the iPhone, the app must be running in the foreground for Bluetooth handshaking to occur, which means users can't use their phones for anything else. It is also a huge battery drain. Android devices don't face the same problem.
In theory, automatic contact traceability can be extremely effective, but only if a large percentage of the population is involved.
Therefore, owners of Apple devices are likely to be asked, among others, to use dongles in the near future.
Privacy concerns
When the token was first announced in early June, there was a public reaction against the government - something which is a relatively rare event in Singapore.
Wilson Low launched an online petition asking for it to be abandoned. Nearly 54,000 people signed up.
"All that is preventing the Singapore government from becoming a state of surveillance is the advent and requires the mandatory use of such a wearable device," said the petition.
"What will come next would be the laws that stipulate that these devices should not be turned off [and must] always remain on a person, thus sealing our fate as a police state. "
Ministers stress that the devices do not record GPS location data or connect to mobile networks, so they cannot be used to monitor a person's movements.
Mr. Cross agrees that from what has been shown to him, dongles cannot be used as locators.
But he adds that the scheme is even less focused on privacy than a model promoted by Apple and Google, which is widely adopted elsewhere.
"At the end of the day, the Ministry of Health can switch from this cryptic secret number that only they know, to a phone number - to an individual," he explains.
In contrast, apps based on the model of Apple and Google warn users if they are at risk, but do not reveal their identity to the authorities. It is up to people to do this when, for example, they register for a test.
Dr Michael Veale, a digital rights expert at University College London, warns of the mission's potential failure.
It provides an example in which a government fighting Covid-19 may want to impose quarantine control. He could do this, he says, by inserting Bluetooth sensors into public spaces to identify dongle users who are out and about when they should self-isolate themselves at home.
"All you have to do is install the physical infrastructure around the world and the data it is collecting can be traced back to Singapore ID numbers," he explains.
"Buildability is the worrying part."
But the officer in charge of the agency responsible for TraceTogether minimizes these concerns.
"There is a relationship of trust between government and people and there is data protection," says Kok Ping Soon, CEO of GovTech.
He adds that he hopes that the public will recognize that health authorities need this data to protect them and their loved ones.
Another reason why Singapore prefers its scheme over that of Apple and Google is that it can provide epidemiologists with more information on the spread of an outbreak.
This was in part the reason why the British government initially resisted the adoption of the technology giants' initiative until its efforts to get around Apple's Bluetooth restrictions managed to rally.
If Singapore's wearable devices work as hoped, other nations may be tempted to follow suit.
"[With more data], you are able to make political decisions that tie restrictions or obligations very carefully only to high-risk activities. Otherwise, you will have many tools left, "comments privacy expert Roland Turner, another member of the group invited by Singapore to inspect the hardware.
"There is perhaps a paradoxical consequence that more freedoms are possible."
