Autentifikacija putem zaporki

master's thesis

• Title (english): Password-based authentication
• Author: Doroteja Grbin
• Mentor: Ante Đerek (mentor)
• Committee member: Ante Đerek (predsjednik povjerenstva)
• Committee member: Stjepan Groš (član povjerenstva)
• Committee member: Marin Golub (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2022-07-06, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Computing

Abstract

Zaporke pružaju osnovnu provjeru autentičnosti korisnika. U Wi-Fi mrežama se najčešće koristi WPA2 protokol koji četverostrukim rukovanjem kriptira poruke raznim ključevima i time pristupna točka dozvoljava korisniku pristup bežičnoj mreži. Time smo osigurali da zlonamjerni klijent koji samo prisluškuje promet ne može direktno saznati zaporku Wi-Fi mreže. Objasnili smo dva glavna pristupa napada na zaporke, a to su mrežni i izvanmrežni napadi. U ovom radu smo demonstrirali postupak ekstrakcije zaporke u Wi-Fi mreži koristeći napad grubom silom, unaprijed izrađenim rječnikom, kombinacijom rječnika ili hibridnim napadom. Alat koji smo za te napade koristili je Hashcat na čiju brzinu, osim vrste napada za određen tip zaporke, ovisi i tip procesora, CPU ili GPU. Temeljem dobivenih informacija o cijeni iz Google Cloud-a, proveli smo analizu sigurnosti Wi-Fi mreža u Hrvatskoj tako da smo skupili dodijeljene zaporke usmjerivača koje se više ne koriste i izračunali potrebnu cijenu za njihovo probijanje.

Abstract (english)

Passwords provide basic user authentication. Wi-Fi networks most commonly use the WPA2 protocol, which encrypts messages with various keys using four-way handshake, allowing the access point to allow the user to access a wireless network. This ensures that a malicious client that only eavesdrops on traffic cannot directly find out the Wi-Fi password. We have explained two main approaches to password attacks, online and offline attacks. In this paper, we demonstrated the process of password extraction in a Wi-Fi network using brute force attack, precomputed dictionary attack, dictionary combination and hybrid attack. The tool we used for these attacks is Hashcat, whose speed, in addition to the type of attack for a particular type of password, also depends on the type of processor, CPU or GPU. Based on the obtained price information from Google Cloud, we conducted an analysis of the security of Wi-Fi networks in Croatia by collecting the assigned router passwords that are no longer used and calculated the required price for breaking them.

• Keywords: mrežni napad; izvanmrežni napad; napad unaprijed izrađenim rječnikom; napad kombinacijom rječnika; hibridni napad; Wi-Fi mreže; WPA2; četverostruko rukovanje
• Keywords (english): online attack; offline attack; attack with a pre-computed dictionary; combination attack; hybrid attack; Wi-Fi networks; WPA2; four-way handshake
• Language: croatian
• URN:NBN: urn:nbn:hr:168:100225
• Study programme: Title: Computing; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka računarstva (magistar/magistra inženjer/inženjerka računarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2023-01-13 10:01:40