Thesis Details

Přenos bezpečnostních opatření z prohlížeče Brave do rozšíření JavaScript Restrictor

Master's Thesis Student: Švancár Matúš Academic Year: 2020/2021 Supervisor: Polčák Libor, Ing., Ph.D.
English title
Porting of Brave Fingerprinting Protection to JavaScript Restrictor

Users of internet browsers are constantly monitored, without their consent. By using the JavaScript APIs, it is possible to obtain various information about the browser, which together form a browser fingerprint, which can then be misused. Therefore, the goal of this work is to use a robust fingerprint protection solution of Brave browser and port it to the JavaScript Restrictor extension. In this work, the problematics of obtaining an fingerprint and countermeasures in the Brave browser are analyzed and then compared with the current protection in the JSR extension. The method of porting of Brave's countermeasures is presented and subsequently the procedure of implementation of these defense elements into the browser extension is described. The resulting implementation has been tested and evaluated, with the new protection appearing to be effective.


browser fingerprinting, Brave, Farbling, JSR, JavaScript Restrictor, Javascript, PriVaricator, FPRandom,  randomized fingerprint

Degree Programme
Information Technology and Artificial Intelligence, Specialization Application Development
defended, grade C
23 June 2021
Zemčík Pavel, prof. Dr. Ing. (DCGM FIT BUT), předseda
Bartík Vladimír, Ing., Ph.D. (DIFS FIT BUT), člen
Holík Lukáš, doc. Mgr., Ph.D. (DITS FIT BUT), člen
Kreslíková Jitka, doc. RNDr., CSc. (DIFS FIT BUT), člen
Orság Filip, Ing., Ph.D. (DITS FIT BUT), člen
Polčák Libor, Ing., Ph.D. (DIFS FIT BUT), člen
ŠVANCÁR, Matúš. Přenos bezpečnostních opatření z prohlížeče Brave do rozšíření JavaScript Restrictor. Brno, 2021. Master's Thesis. Brno University of Technology, Faculty of Information Technology. 2021-06-23. Supervised by Polčák Libor. Available from:
    author = "Mat\'{u}\v{s} \v{S}vanc\'{a}r",
    type = "Master's thesis",
    title = "P\v{r}enos bezpe\v{c}nostn\'{i}ch opat\v{r}en\'{i} z prohl\'{i}\v{z}e\v{c}e Brave do roz\v{s}\'{i}\v{r}en\'{i} JavaScript Restrictor",
    school = "Brno University of Technology, Faculty of Information Technology",
    year = 2021,
    location = "Brno, CZ",
    language = "czech",
    url = ""
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