Europol has proposed solutions to address some of the challenges posed by privacy-enhancing technologies found in Home Routing, which pose a challenge for law enforcement agencies in intercepting communications during criminal investigations as a result of these technologies. There was a previous report by the agency in its Digital Challenges series in which it discussed the difficulty of gathering admissible evidence during investigations due to end-to-end encryption on communication platforms. 

This is the name given to an in-home routing system used by telecommunications companies to allow customers to send traffic to their home network, from calls, messages, and internet data, even when they are away from home. In a new report that was published by the EU Innovation Hub for Internal Security, it was examined how users can uphold citizens' privacy while simultaneously facilitating criminal investigations and prosecutions. 

There is no doubt that encryption is one of the most important means by which private communications may be protected. Meanwhile, it is also conducive to allowing threat actors to always remain hidden from the eyes of law enforcement to carry out their malicious activities. Companies must understand the needs, challenges, and priorities of their stakeholders within the Justice and Home Affairs (JHA) community to take the necessary measures to preserve the fundamental rights of the citizens of Europe while maintaining a safe environment. 

The privacy-enhancing technologies (PETs) that can be applied in Home Routing support data encryption at the service level, and the devices that are subscribed in the home network exchange session-based keys with the provider. In the case of the home network provider using PET technology, all traffic remains encrypted, as the key is inaccessible to both the home network's backend and the visiting network, which serves as a forwarder. It is due to this setup that authorities are prevented from obtaining evidence through the use of local Internet service providers (ISPs) as part of lawful interception activities. 

It explains that by implementing Home Routing, any suspect using a foreign SIM card cannot be intercepted after that device is deployed, says the European agency in a press release. If this is the case, then it may be necessary for police forces to rely on the cooperation of foreign service providers or issue a European Investigation Order (EIO), which can take significantly longer than it would normally take to complete an investigation, especially in cases where emergency interceptions are required; for example, replying to an EIO can take up to four months in most cases. 

There is no doubt that criminals are aware of this loophole in the law and are exploiting it to avoid being caught by law enforcement in their respective countries, as summarized by the European agency. The European Union's law enforcement agency Europol is appealing to stakeholders to consider two possible solutions that would effectively eliminate delays and procedural frictions associated with lawful communication interceptions. 

One of the first variants being considered is the enforcement of a regulation in the European Union that disables PE in the home routing protocol. It will be possible for domestic service providers to intercept calls made by individuals who are using foreign SIM cards but they will not have to share information about the person of interest with outside parties. A spokesperson for the agency said that by using this solution, both roaming subscribers, as well as subscribers in their local area, will be able to take advantage of the same level of encryption as communication through their national SIM card. 

However, subscribers abroad do not benefit from the added encryption of their home country, which is included in the subscription package. Furthermore, there is a second proposal where companies propose implementing a cross-border mechanism that allows law enforcement agencies within the European Union to issue interception requests that are promptly handled by the service providers to assist law enforcement agencies. Europol has identified two potential solutions to address the challenges posed by Home Routing and mobile encryption in criminal investigations. 

The first solution allows Privacy-Enhancing Technologies (PET) to be enabled for all users. However, this could result in a service provider in another EU member state learning about individuals of interest in an investigation, which may not be desirable. The second proposed solution involves establishing a mechanism for rapidly processing interception requests from service providers in other EU member states. Europol emphasizes that these two solutions are merely possible avenues for safeguarding and maintaining existing investigatory powers. 

The agency's goal is to highlight the impact that Home Routing encryption has on investigations, urging national authorities, legislatures, and telecommunications service providers to collaborate in finding a viable solution to this problem.