Monthly Archives: December 2017

MSc thesis: Security of Loyalty Cards Used in Estonia

This thesis identifies the card technologies used in loyalty programs across Estonia. These technologies include magnetic-stripe cards, contactless cards (in the form of MIFARE Classic, MIFARE Ultralight, MIFARE DESFire EV1 and low frequency RFID cards) and a smart card known as the Estonian electronic identification card (ID card). Each card type implements its own security features to prevent cloning and/or unauthorized access to the content stored on the card. The contents of each card was read and the method in which it was used in the system analysed. In the cases where possible a clone of the card was created and tested against the real system to verify that it passed the authentication procedures.

This is MSc thesis from TUT Cyber Security curriculum. The thesis was defended in June 2017.

The thesis analyzed cloneability aspects of the loyalty cards used in Estonia. While the magnetic-stripe cards are known to be trivially cloneable, the study also analyzed bunch of contact-less cards: MyFitness, Elron, Tallinn Bus Card, ISIC, SEB ISIC, Tartu Bus Card, Rimi Card. Only the Rimi and Elron card was found to withstand known cloning attacks.


Estonian Defence Forces to set up Cyber Command of 300 hackers

The Estonian Defence Forces next year will create Cyber Command, which, if necessary, will also take cyber attacks against both virtual and physical targets.

“It will begin to carry out cyber-attacks in the entire spectrum, which means both defense and, if necessary, attack,” explained the undersecretary of the Ministry of Defense Erki Kodar meeting today in Tallinn with the international press. Kodar pointed out that Estonia does not plan to use the cybersecurity’s capability to act only in cyberspace, but also, if necessary, in other areas of warfare, in other words to attack physical targets.

“All of this activity must, of course, be based on Estonian law and in accordance with international law,” Kodar confirmed.

The unit should begin work on August 1, 2018 and achieve full capacity for work by 2020. By that time, 300 people should serve the cyber command. The cyber command is not very common in the world or in NATO allied countries. A similar entity already works in the United States, the United Kingdom, Germany, France and the Netherlands. Next year Estonia will be added to the list.

The number 300 is a big number for the small Estonia. This will be very expensive for the Defence Forces, because these specialists are paid a lot in the private sector.


Smart-ID paper: Server-Supported RSA Signatures for Mobile Devices

We propose a new method for shared RSA signing between the user and the server so that: (a) the server alone is unable to create valid signatures; (b) having the client’s share, it is not possible to create a signature without the server; (c) the server detects cloned client’s shares and blocks the service; (d) having the password-encrypted client’s share, the dictionary attacks cannot be performed without alerting the server; (e) the composite RSA signature “looks like” an ordinary RSA signature and verifies with standard crypto-libraries. We use a modification of the four-prime RSA scheme of Damgård, Mikkelsen and Skeltved from 2015, where the client and the server have independent RSA private keys. As their scheme is vulnerable to dictionary attacks, in our scheme, the client’s RSA private exponent is additively shared between server and client. Our scheme has been deployed and has over 200,000 users.

The paper was published in proceedings of the conference ESORICS 2017, Oslo, Norway, September 11-15, 2017.

The paper contains several pages of cryptographic proofs. The RSA key generation involves “l-safe” primes, which is not a standard practice in generating RSA primes. This is worrisome, especially after it became known that the flaw in ID card was caused by other instance of nonstandard RSA prime generation.


TallinnSec meetup: DevSec, 4G broadband modem pwning, Database Hoarding and Certbot

Tuesday, December 12, 2017, 17:00 to 20:00.
Technopolis Ülemiste, Lõõtsa 6, 2nd floor
Room name: Helsinki

17:10 – Sponsor greetings from Märt Ridala (Solita OÜ)
17:20 – Antti Virtanen: DevSec
17:50 – Iiro Uusitalo: WAN-to-LAN exploitation of 4G broadband modem
18:10 – Shamil Alifov: Database Hoarding. For fun and profit.
18:40 – Joona Hoikkala: Road ahead for encrypted web with Certbot and Let’s Encrypt
19:10 – Stefano Alberico: Communication solution based on end-to-end hardware encryption