Högskolan i Skövde

The use of encryption is increasing, and while that is good for cybersecurity it is a core challenge for digital forensics. Encrypted information cannot be analyzed unless it is first decrypted, which is a complex and time-consuming process. Using a brute force attack to guess the password used for encryption is deemed impractical as even a simple password, being long enough, could take weeks, months, or even years to find. A more feasible approach is to use a dictionary attack where each word in a list is tested. However, a dictionary attack is only successful if the password is in the list, making the process of creating that list a crucial part of decrypting passwords. This research builds on existing literature showing that users commonly use strategies to create passwords, and the aim is to propose a method for creating dictionaries that are grounded in theories of password construction. An initial model was developed using a selective literature review with the purpose of identifying common elements included in biographical passwords, and in what order the elements are used. To improve the model, the study utilized semi-structured interviews with forensic experts from the Swedish police and the Swedish National Forensic Center (NFC). The main contribution of this research is a readily available model for creating dictionaries that can be used by practitioners. The model can also serve as a theoretical contribution that describes how users commonly construct biographical passwords.