Mathias Payer

---

concerns about the risks associated with the provision of a go-it-alone UK coronavirus contact-tracing app, leading to further delays.

A second version of the smartphone software has been started due to test on The Isle of Wight on Tuesday, but the government has decided for the postponement of the hearing.

the Ministers are developed, taking into account the conversion of the app on tech from Apple and Google.

But also the countries of the examination, the model on problems of their own.

health Secretary to Matt Hancock had originally told the NHS Covid-19-app to be started, via England and possibly other parts of the UK - 1. June.

But later said the government had decided that it would be better to establish a network of human contract Tracer first.

But The Bbc has found out that one of the main reasons the initiative is behind schedule, the developers estimate distance problems with the Bluetooth as a means to.

Even so, you still believe that you are better prepared to meet The Challenge , as the colleagues abroad, to work under restrictions by the two U.S. tech companies.

using the Bluetooth handshake

contact-tracing apps are designed to prevent a second wave of infections by the logging of the if Two People are in close proximity to each other and for how long.

If a user later Tested positive for the disease, The Records will be used to determine how likely it is that they infected The Other . If required, triggers an alert, in order to prevent the further spread of The Virus .

the UK has adopted what is known as a "Central" approach, which means that the contact matching process is performed on a remote server computer. One advantage is, it provides epidemiologists, more and more data to combat the pandemic. France and India are other countries the model of takeovers.

by contrast, Apple and Google "decentralized" approach, the games leads to the phones themselves, not on the site, the better the privacy of The Users of protects.

Poland changed his app from a centralized to decentralized approach on Tuesday. Switzerland, Ireland , Germany, Italy and Latvia have adopted, among other things, the tech giant " design.

Both systems rely on to work on the Bluetooth "handshake" to.

with the number 10 is concerned that the iPhones always recognize each other, because of the restrictions Apple imposes on apps, to make your own model.

But the UK team, a workaround has been devised, and is more concerned about other restrictions on the use of Bluetooth.

track issues

Some of these questions were already in a study.

It highlighted problems in the use of the received Bluetooth signal strength as a means to estimate distance.

researchers warned signal strength "can vary considerably" depending on:

The Report highlighted some disturbing results, when Singapore trace together has been Tested to app.

Ireland -the police are among the organizations, the testing of a contact tracing app prior to a planned nation-wide introduction

An experiment in a stationary train car found that, when the user moves from a distance of 3. 5m (11. 5ft) on 4m, signals became stronger rather than weaker, because of The Way metallic objects reflect the radio waves.

A study in a supermarket, the received signal strength was the same whether Two People were walking near together, or 2m apart.

Follow-up tests with the Apple-Google-tech are currently in progress.

"The Work is ongoing, but the preliminary results are largely in line with previous observations," said Dr. Brendan Jennings, who has been tasked with the assessment of the effectiveness of Ireland 's Covid-19 app.

Concealed data

The team behind Switzerland SwissCovid app, is conducting tests of its own.

the Bluetooth-measurement-in-chief believes that the Problem is partly addressed by a series of measurements over a period of Five Minutes or more.

But he added that Apple and Google curbs it had placed on what could be achieved.

"Google and Apple API [application programming interface] limits the amount of raw data, the actually exposed to the app," Prof Mathias Payer , The Bbc said.

"For maximum benefit, we get all the different measurements, but this has implications for privacy. "

Swiss MPs have given permission for the country of the contact tracing app will be launched that do not get nationwide

Apps with Google and Apple to see the tech, the actual signal strength, but rather one of the three values, on the basis of the calculations used to normalize the different ways that Bluetooth behaves on different phones,

however, the UK team currently can the measurements be obtained directly.

the responsible believe, a further advantage is their Central approach is that the data involved are processed on the server, because it would be too tiring a task that can be done on smartphones.

But it is a part of your challenge to communicate this to Baroness Dido Harding - head of the wider Test and Trace program and 10 Downing Street itself.

A spokesman for the Prime Minister declined to comment.

contact tracing, google, coronavirus pandemic, apple

Source of news: bbc.com