Secluded in the conclave - expert on technical possibilities

On Wednesday, the doors to the Sistine Chapel will close behind the cardinal electors. Isolated from the world, they are to elect a successor to Pope Francis. How will the churchmen in the conclave manage not to use mobile phones or other mobile devices? The Catholic News Agency (KNA) asked Luise Allendorf-Hoefer (60). The engineer is an expert in communications technology and works as a curator at the Deutsches Museum in Munich.

Question: Mrs Allendorf-Hoefer, the smartphone has long since become a faithful companion for cardinals too. How can it be technically ensured that nobody uses it secretly during the conclave?

Allendorf-Hoefer: That's a very exciting topic because it's about the security of wireless transmission. In the case of the conclave, the interference is of course intentional. There are many ways to sabotage wireless connections that can be realised technically with a manageable amount of effort. You need to know this: Basic radio technology is based on the generation, propagation and reception of electromagnetic waves. Its most important feature is the radio frequency. All mobile phone and wifi applications operate on such defined bands, which are allocated by regulatory authorities and international bodies.

Question: What will the Vatican technicians do?

Allendorf-Hoefer: Definitely switch off the wifi router first. But even though I'm not privy to the Vatican's secrets, two established methods will probably be used there: detecting wirelessly communicating electronics and destroying the signal quality.

Question: What does that look like in practice?

Allendorf-Hoefer: With radio measuring devices such as scanners or detectors, locating mobile phones, laptops or tablets within spatial limits is no problem. Even a mobile phone in standby mode emits recurring radio signals that can be detected. With the right measuring device, even an experienced radio amateur can judge whether such a device is switched on in the vicinity. However, this ultimately only identifies whether a device is currently in use. Presumably the Sixtina is scanned beforehand using this method.

Question: And the other method?

Allendorf-Hoefer: Mobile phone connections are made using well-known frequency bands. In order to transmit data and voice securely, a certain signal quality is technically required. This must be destroyed accordingly. Even if a mobile phone connection is stable and secure, it can be destroyed by so-called jammers - jamming transmitters on the appropriate frequency. Various technical phenomena such as masking or overdriving are used for this. Any decoding or readability of the transmission is thus destroyed.

Question: Does the Vatican have such equipment?

Allendorf-Hoefer: As far as I know, the Sistine Chapel even has such jammers and their associated antennas permanently installed. This means that wireless communication with the outside world can be completely blocked or sabotaged. It can be assumed that this is also installed in the cardinals' guest rooms.

Question: The Catholic Church as a role model for jammers?

Allendorf-Hoefer: Since the development of radio technology, jammers have always been considered. In many cases, they were unintentional, as radio waves are not bound by spatial boundaries. Unfortunately, this also makes acts of sabotage possible. Remember that satellite communication, navigation and GPS positioning are used for civil and military purposes. At sea, on land, in the air, even the energy infrastructure relies on radio technology. However, the conclave is not regarded as the driving force behind these - admittedly exciting - scanner and jammer technologies. But thick walls alone, as church buildings often have, are not enough protection.