high a price being charged. Receipts are not given, and the trips can be checked online only after a few days, making it hard to verify that the correct amount was paid. It was expected that Skånetrafiken in Scania in Sweden would implement a system akin to the Danish. Therefore, the Rejsekort system was prepared to work with the Scanian, so as to allow passengers to easily travel over the Øresund Bridge. The current cross border paper tickets are also accepted on local traffic, and should do so also in the future. Skånetrafiken did in 2009 introduce a different electronic card system, which is incompatible with Rejsekort, leading to separate Danish Rejsekort check-in/check-out readers being installed at Øresundståg stops in Malmö (i.e. Hyllie, Triangeln, and Malmö C stations). The current Skånetrafiken system is electronic only for buses (card or QR code on the Skånetrafiken app), while for trains either an electronic ticket (card or app) or a paper ticket can be used. Neighbour counties in the north introduced the same system but under their own names. The implementation of Rejsekortet is considered to be one of the biggest IT scandals in Denmark. This due to the not very successful end product, the doubled price-tag and the extreme delay in the original project plan. Technology The card technology is MIFARE Classic. The card has a 4 kilobyte electrically erasable programmable read-only memory (EEPROM) which can be written to using RFID. The card also contains a chip by NXP Semiconductors which implements a proprietary cryptography scheme called CRYPTO1, which was fully reverse-engineered in 2008. A Practical Attack on the MIFARE Classic was published in 2008 by a group at Radboud University Nijmegen. The ride history is stored on the card unencrypted and can be read by anyone. There are mobile apps made by third parties which can achieve this. Timetable for implementation The Rejsekort system was tested between Roskilde and Tølløse in December 2007. Plans to roll the system out to the whole of Zealand in 2008 and 2009 have been shelved due to delays, and have instead been replaced with the following timetable: Testing between Taastrup and Holbæk at the end of 2008 Rollout to paying customers between Taastrup and Holbæk at the start of 2009 South Zealand at the end of 2009 West Zealand in the beginning of summer 2010 Capital Region of Denmark (essentially Copenhagen and surrounding areas) in