The 3 Seas Digital Highway

Year registered: 2018
3SI countries proposing the project:


Participating 3SI countries:

Austria, Czechia, Latvia, Bulgaria, Lithuania, Poland, Croatia, Estonia, Hungary, Romania, Slovakia, Slovenia

Partner countries:


* not part of the 3Seas Initiative
Main objectives:

Project is temporarily put on hold due to the war in Ukraine

  1. Joint of cross-border cyber resilient digital infrastructure projects (the 3 Seas Digital Highway) that enable better and more secure data transfer from North to South of the region and bridge the gaps in the communication infrastructure, including fibre optics and 5G technology infrastructure.
  2. Provision of potential to grow for the data economy.
Short description:
  • The concept of connecting South and North of the region should be further expanded to include a cyber resilient data transmission element. The Three Seas should be linked via the so-called 3 Seas Digital Highway. In 2015, the Baltic Highway, a fibre-optic network connecting Tallinn and Frankfurt via Riga, Vilnius, Warsaw and Berlin, was officially launched. Like many other similar investment projects, it aims to connect Western and Eastern Europe. The Three Seas Initiative, connecting the Baltic Sea, the Adriatic Sea and the Black Sea, should also consider, as its integral part, the development of cyber resilient digital infrastructure along the north-south axis. This will help complement the map of digital connections that are currently the foundation underpinning digitally evolving economies. The concept of supplementing gas and road infrastructures being built as part of the Three Seas Initiative with a resilient digital component should be further elaborated and extended to all the countries participating in the Initiative. The synergy may additionally shorten the time required for the investment process and lower the cost of the enterprise.
  • The construction of the 3 Seas Digital Highway can help develop modern 5G wireless technology and the whole ecosystem that is founded on it, common to all Three Seas countries. In order to build the 3 Seas Digital Highway, it is necessary to ensure data confidentiality, integrity and availability. Fibre-optic cables are not only located underground or at the surface, but also lie in the oceans and run along the seabed. Although it is difficult to tap these cables, it is possible to do so at junction points. Successful attacks on fibre-optic cables can cause the country to be deprived of global Internet access. Ensuring resilience of the undersea and terrestrial fibre-optic infrastructure to damage and new threats requires encryption and supervision. On the other hand, in order to build the confidence of both citizens and the industry in the 5G technology, it is necessary to take into account the cyber resilience of the entire multi-layered fifth generation network architecture, which, in addition to high technical parameters, should be primarily characterised by reliability and integrity. Hence, it is crucial to approach 5G security in a comprehensive manner, taking into account telecommunication service operators, cloud-based service providers, vertical and virtual private 5G networks. Only such an approach regarding the 5G/cyber security may be assured, not only at the level of the network, but also in the higher layers related to the provision of specific services. The development of common security models and good practices related to the construction of 5G networks may take place not only on the designated international forums, but also as part of the Digital 3 Seas initiative, as the technology is now taking off around the globe.

Contact person:

Mr. ADAM ROGOWSKI, Chief Specialist, Digital Policy Department, Chancellery of the Prime Minister, tel. +4822 245 5842, email:, :

Calendar of implementation:
  • 2020-2021

    preparation of the subject of the contract regarding the feasibility study of the 3SI Digital Highway and searching for its potential contractors;

    analysis of various financing options for the project, especially based on new financial instruments currently being launched by the EU for the period 2021-2027.

    analysis of the possibility of locating investments along the Via Carpatia road infrastructure.

  • after 2021

    Implementation timeline not defined on this stage of the project.


Budget not defined at this stage of the project.

Financing sources:

Budget not defined at this stage of the project.