Caesarcipher is a commonly known encryption method although it is known for being unsure, even long before computers were invented. Even though it is unsure it can still be used for cryptography, JackTheRidder consists of two main algorithms where one of them is based on the Caesarcipher. With many rotations of Caesarciphers on different parts of texts, like many Vigenerecryptos of different sizes overlapping each other, makes the encryption secure. The other main algorithm of JackTheRidder is based on the Collatz Conejcture, which is a famous unsolved mathematical problem. This algorithm counts the amount of steps it takes before the chosen number reaches 1 and then moves the letter with those steps which results in the encryption. The amount of steps is a result from a positive integer going through Collatz Conjecture, which divides the integer if its even and uses (3𝑥+1)/2 if the integer is odd. The algorithm then moves to the next character to encrypt and adds one to the integer used. JackTheRidder is an encryption method created by the authors of this project and further will be analyzed in this essay. The focus of this essay is to analyze how Collatz Conjecture and Caesarcipher functions in encryption methods. JackTheRidder is going to be examined through literature study and experiments. There are three criterias that JackTheRidder is going to be analyzed from; security, robustness and efficiency. The results indicate that JackTheRidder needs to be optimized and be written in machine code for it to be able to get better implemented in society. JackTheRidder is proven to be better than AES in the chi2 test which is an indicator that it might be a viable option for replacement. Overall in the experiments, JackTheRidder held a high level which is a positive outcome but still it is not guaranteed to be secure enough to be implemented into the society at this stage of developement.

Det är sedan länge känt, både bland företag och i den akademiska världen, att det krävs strukturerade arbetsmetoder för att lyckas med storskalig programvaruutveckling. Vilka metoder som fungerar bäst är det svårt att göra ett generellt uttalande om eftersom detta till stor del är situationsberoende. Det existerar en ansenlig mängd metoder och processer som finns beskrivna i detalj av deras förespråkare, men ingen metod fungerar felfritt i alla situationer. I den här rapporten beskrivs de metoder en projektgrupp tillämpade under ett kandidatarbete i programvaruutveckling, och konsekvenserna dessa fick för den slutgiltiga produkten. Gruppen har kommit fram till att värde har skapats för kunden genom att implementera kundens begärda system, en interaktiv webbapplikation. Underhållbarhet har uppnåtts genom att följa en kodstandard, tillämpa parprogrammering och kodgranskningar samt publicera koden som öppen källkod. Att under möten diskutera gruppmedlemmarnas välmående bidrog till bättre sammanhållning och stämning och därmed ett bättre slutresultat. Många av gruppens svårigheter hade lösts om gruppen haft ett dedikerat kontor. Förhoppningen är att de erfarenheter och den kunskap som gruppen tillgodogjort sig under projektet, och dokumenterat i den här rapporten, ska komma till nytta för både projektmedlemmarna och rapportens läsare.

When the use of encryption amongst the regular computer user grows morewidespread than ever it makes the life of the IT-forensics experts difficult.Hampering the judicial investigations that otherwise could have lead to convictions. In this report we will treat the subject of crypto analysis with a focus on decrypting files and devices encrypted with the software TrueCrypt. A solution will be presented that can facilitate the future work involving encryption. The application DFEAT that has been developed during the writings of this report is faster than the corresponding software EFDD, and attacks both partitions and bitwise copies of entire harddrives where PKF fails.DFEAT is a lightweight application that is almost 50 times smaller compared to EFDD and 200 times smaller than PKF's portable version.