KeeLoq and Electronic Access Control

In real estate and vehicles there is an increasing demand for the comfort of wireless technology. Transponders, contactless smartcards and remote door openers are widely employed to replace conventional mechanical key locking systems. Our scientific analyses show, that the mechatronic locking systems – although using mature mechanical security technology – often suffer from vulnerabilities within the electronic system, the employed cryptography or conceptual weaknesses. The protection mechanisms can then often be thwarted by means of rather simple and efficient methods, such that adversaries may, e.g., copy electronic keys or deactivate alarm systems.

At the example of the KeeLoq© system – a system widely employed for garage door remotes – and many other remote keyless entry systems, history has shown that the employed protection mechanisms fail to resist determined attackers. Due to the usage of radio interfaces the impact of successful attacks are much more severe than in conventional mechanical systems, as there is no need for an attacker to have physical access to the targeted system.


On the Power of Power Analysis in the Real World: A Complete Break of the KeeLoq Code Hopping Scheme. Tho­mas Ei­sen­barth, Timo Kas­per, Amir Mo­ra­di, Chris­tof Paar, Mahmoud Sal­ma­si­z­adeh, Mo­ham­mad T. Man­zu­ri Shal­ma­ni. 28th In­ter­na­tio­nal Cryp­to­lo­gy Con­fe­rence — CRYP­TO 2008. Santa Bar­ba­ra, Ca­li­for­nia, USA. PDF

Breaking KeeLoq in a Flash. Mar­kus Kas­per, Timo Kas­per, Amir Mo­ra­di, Chris­tof Paar. 2nd In­ter­na­tio­nal Con­fe­rence on Cryp­to­lo­gy in Af­ri­ca, Pro­gress in Cryp­to­lo­gy – AF­RI­CA­CRYPT 2009. Gam­marth, Tu­ni­sia. PDF

A New Remote Keyless Entry System Resistant to Power Analysis Attacks. Amir Mo­ra­di, Timo Kas­per. 7th In­ter­na­tio­nal Con­fe­rence on In­for­ma­ti­on, Com­mu­ni­ca­ti­ons and Si­gnal Pro­ces­sing, ICICS 2009. Macau, China. PDF

Cryptanalysis of KeeLoq with COPACOBANA. Mar­tin No­vot­ny, Timo Kas­per. Spe­cial-pur­po­se Hard­ware for At­ta­cking Cryp­to­gra­phic Sys­tems SHARCS 2009. Lausan­ne, Swit­z­er­land. PDF

Sicherheit moderner Funktüröffnersysteme. Thomas Eisenbarth, Timo Kasper, Christof Paar.
Datenschutz und Datensicherheit – DuD Volume 32 Ausgabe 8 – August 2008. PDF (German)

Torschlusspanik: Sicherheitslücken durch Seitenkanalattacken. Thomas Eisenbarth, Timo Kasper, Christof Paar. iX Magazin für professionelle Informationstechnik Ausgabe 9/2008 (German)