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Japan releases Covid-19 contact tracing app

The Cocoa app notifies users if they’ve been in close contact with someone who tested positive for coronavirus

Emma Steen
Written by
Emma Steen

[Update, July 15] According to NHK, the Covid-19 contact tracing app is up and running again today after a glitch in the system has been fixed. The free app Cocoa was designed to notify users if they have come into close contact (ie, within one-metre radius for more than 15 minutes) with someone who was tested positive for coronavirus. The health ministry recommends users to install the latest app update before use. As of July 14, the app has seen 6.95 million downloads.


[Update, June 24] Due to a glitch in the system, the Ministry of Health, Labor and Welfare have temporarily stopped the app from sending alerts to users until the issue is resolved. The app was designed to notify users if they came into close contact with someone who was recently infected with the Covid-19 coronavirus. However, an app defect meant that people could input random numbers in place of an official ministry-issued, individually unique processing number to report testing positive. According to the Japan Times, the app did not appear to send false alerts to other users, but the ministry is working to fix the app within a week. As of Tuesday morning, the app has been downloaded 3.71 million times. 


[June 22] Along with social distancing rules and travel bans to slow the spread of the Covid-19 coronavirus, several countries have implemented contact tracing apps to help users track whether they’ve recently come into contact with people who tested positive for the virus. On June 19, the Japanese government launched its own contact tracing app nicknamed Cocoa, which is free to download on Android and iOS devices. 

The app, which hit 2.7 million downloads as of June 21, operates using your phone’s Bluetooth signals to automatically record and track your movements and relay that information as encrypted data. It will not release your phone number or personal information to other users, but will notify you if you have spent 15 minutes or longer within a metre of someone who has tested positive for the virus.

Cocoa will not tell you when and where the contact took place, but instead will identify the user with their ‘contact code’, a randomly generated series of numbers which is issued to each user. The app will clear your data every two weeks, but will notify you if you’ve been in close contact with a virus carrier within that period, so you’ll know to get tested. 

The Japan Times reports that, despite government assurances that the app does not collect personal information and send it to the government, the Bluetooth tracking system still raises some concerns among people who don’t want their movements to be monitored. According to current research, at least 60 percent of the population must use the app for it to be effective. While Prime Minister Shinzo Abe assured the public that they can use the app without worrying about personal information being leaked, users can disable Bluetooth tracking on the app at any time. 

For advice on how to go out safely in Tokyo, or anywhere for that matter, check our guide.

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