Now showing 1 - 10 of 53
  • Publication
    Hierarchical Bloom Filter Trees for Approximate Matching
    (Journal of Digital Forensics, Security and Law, 2018-01) ; ;
    Bytewise approximate matching algorithms have in recent years shown significant promise in detecting files that are similar at the byte level. This is very useful for digital forensic investigators, who are regularly faced with the problem of searching through a seized device for pertinent data. A common scenario is where an investigator is in possession of a collection of "known-illegal" files (e.g. a collection of child abuse material) and wishes to find whether copies of these are stored on the seized device. Approximate matching addresses shortcomings in traditional hashing, which can only find identical files, by also being able to deal with cases of merged files, embedded files, partial files, or if a file has been changed in any way. Most approximate matching algorithms work by comparing pairs of files, which is not a scalable approach when faced with large corpora. This paper demonstrates the effectiveness of using a "Hierarchical Bloom Filter Tree" (HBFT) data structure to reduce the running time of collection-against-collection matching, with a specific focus on the MRSH-v2 algorithm. Three experiments are discussed, which explore the effects of different configurations of HBFTs. The proposed approach dramatically reduces the number of pairwise comparisons required, and demonstrates substantial speed gains, while maintaining effectiveness.
  • Publication
    Leveraging Decentralisation to Extend the Digital Evidence Acquisition Window: Case Study on BitTorrent Sync
    File synchronization services such as Dropbox, Google Drive, Microsoft OneDrive, Apple iCloud, etc., are becoming increasingly popular in today’s always-connected world. A popular alternative to the aforementioned services is BitTorrent Sync. This is a decentralized/cloudless file synchronization service and is gaining significant popularity among Internet users with privacy concerns over where their data is stored and who has the ability to access it. The focus of this paper is the remote recovery of digital evidence pertaining to files identified as being accessed or stored on a suspect’s computer or mobile device. A methodology for the identification, investigation, recovery and verification of such remote digital evidence is outlined. Finally, a proof-of-concept remote evidence recovery from BitTorrent Sync shared folder highlighting a number of potential scenarios for the recovery and verification of such evidence.
  • Publication
    The Case for a Collaborative Universal Peer-to-Peer Botnet Investigation Framework
    (Academic Conferences and Publishing International Limited, 2014-03-25) ;
    Peer to Peer (P2P) botnets are becoming widely used as a low overhead, efficient, self maintaining, distributed alternative to the traditional client/server model across a broad range of cyberattacks. These cyberattacks can take the form of distributed denial of service attacks, authentication cracking, spamming, cyberwarfare or malware distribution targeting on financial systems. These attacks can also cross over into the physical world attacking critical infrastructure causing its disruption or destruction (power, communications, water, etc.). P2P technology lends itself well to being exploited for such malicious purposes due to the minimal setup, running and maintenance costs involved in executing a globally orchestrated attack, alongside the perceived additional layer of anonymity. In the ever evolving space of botnet technology, reducing the time lag between discovering a newly developed or updated botnet system and gaining the ability to mitigate against it is paramount. Often, numerous investigative bodies duplicate their efforts in creating bespoke tools to combat particular threats. This paper outlines a framework capable of fast tracking the investigative process through collaboration between key stakeholders.
  • Publication
    Network Investigation Methodology for BitTorrent Sync: A Peer-to-Peer Based File Synchronisation Service
    High availability is no longer just a business continuity concern. Users are increasingly dependant on devices that consume and produce data in ever increasing volumes. A popular solution is to have a central repository which each device accesses after centrally managed authentication. This model of use is facilitated by cloud based file synchronisation services such as Dropbox, OneDrive, Google Drive and Apple iCloud. Cloud architecture allows the provisioning of storage space with 'always-on' access. Recent concerns over unauthorised access to third party systems and large scale exposure of private data have made an alternative solution desirable. These events have caused users to assess their own security practices and the level of trust placed in third party storage services. One option is BitTorrent Sync, a cloudless synchronisation utility provides data availability and redundancy. This utility replicates files stored in shares to remote peers with access controlled by keys and permissions. While lacking the economies brought about by scale, complete control over data access has made this a popular solution. The ability to replicate data without oversight introduces risk of abuse by users as well as difficulties for forensic investigators. This paper suggests a methodology for investigation and analysis of the protocol to assist in the control of data flow across security perimeters.
      667Scopus© Citations 15
  • Publication
    Evaluation of Digital Forensic Process Models with Respect to Digital Forensics as a Service
    (Academic Conferences And Publishing International Limited, 2017-06-12) ; ;
    Digital forensic science is very much still in its infancy, but is becoming increasingly invaluable to investigators. A popular area for research is seeking a standard methodology to make the digital forensic process accurate, robust, and efficient. The first digital forensic process model proposed contains four steps: Acquisition, Identification, Evaluation and Admission. Since then, numerous process models have been proposed to explain the steps of identifying, acquiring, analysing, storage, and reporting on the evidence obtained from various digital devices. In recent years, an increasing number of more sophisticated process models have been proposed. These models attempt to speed up the entire investigative process or solve various of problems commonly encountered in the forensic investigation. In the last decade, cloud computing has emerged as a disruptive technological concept, and most leading enterprises such as IBM, Amazon, Google, and Microsoft have set up their own cloud-based services. In the field of digital forensic investigation, moving to a cloudbased evidence processing model would be extremely beneficial and preliminary attempts have been made in its implementation. Moving towards a Digital Forensics as a Service model would not only expedite the investigative process, but can also result in significant cost savings - freeing up digital forensic experts and law enforcement personnel to progress their caseload. This paper aims to evaluate the applicability of existing digital forensic process models and analyse how each of these might apply to a cloud-based evidence processing paradigm.
  • Publication
    Smarter Password Guessing Techniques Leveraging Contextual Information and OSINT
    In recent decades, criminals have increasingly used the web to research, assist and perpetrate criminal behaviour. One of the most important ways in which law enforcement can battle this growing trend is through accessing pertinent information about suspects in a timely manner. A significant hindrance to this is the difficulty of accessing any system a suspect uses that requires authentication via password. Password guessing techniques generally consider common user behaviour while generating their passwords, as well as the password policy in place. Such techniques can offer a modest success rate considering a large/average population. However, they tend to fail when focusing on a single target - especially when the latter is an educated user taking precautions as a savvy criminal would be expected to do. Open Source Intelligence is being increasingly leveraged by Law Enforcement in order to gain useful information about a suspect, but very little is currently being done to integrate this knowledge in an automated way within password cracking. The purpose of this research is to delve into the techniques that enable the gathering of the necessary context about a suspect and find ways to leverage this information within password guessing techniques.
      35Scopus© Citations 8
  • Publication
    Electromagnetic side-channel attacks: Potential for progressing hindered digital forensic analysis
    Digital forensics is fast-growing field involving the discovery and analysis of digital evidence acquired from electronic devices to assist investigations for law enforcement. Traditional digital forensic investigative approaches are often hampered by the data contained on these devices being encrypted. Furthermore, the increasing use of IoT devices with limited standardisation makes it difficult to analyse them with traditional techniques. This paper argues that electromagnetic side-channel analysis has significant potential to progress investigations obstructed by data encryption. Several potential avenues towards this goal are discussed.
      25Scopus© Citations 14
  • Publication
    SoK: Exploring the State of the Art and the Future Potential of Artificial Intelligence in Digital Forensic Investigation
    Multi-year digital forensic backlogs have become commonplace in law enforcement agencies throughout the globe. Digital forensic investigators are overloaded with the volume of cases requiring their expertise compounded by the volume of data to be processed. Artificial intelligence is often seen as the solution to many big data problems. This paper summarises existing artificial intelligence based tools and approaches in digital forensics. Automated evidence processing leveraging artificial intelligence based techniques shows great promise in expediting the digital forensic analysis process while increasing case processing capacities. For each application of artificial intelligence highlighted, a number of current challenges and future potential impact is discussed.
      58Scopus© Citations 33
  • Publication
    Forensic Analysis and Remote Evidence Recovery from Syncthing: An Open Source Decentralised File Synchronisation Utility
    Commercial and home Internet users are becoming increasingly concerned with data protection and privacy. Questions have been raised regarding the privacy afforded by popular cloud-based file synchronisation services such as Dropbox, OneDrive and Google Drive. A number of these services have recently been reported as sharing information with governmental security agencies without the need for warrants to be granted. As a result, many users are opting for decentralised (cloudless) file synchronisation alternatives to the aforementioned cloud solutions. This paper outlines the forensic analysis and applies remote evidence recovery techniques for one such decentralised service, Syncthing.
      33Scopus© Citations 5
  • Publication
    Enabling non-expert analysis of large volumes of intercepted network traffic
    Telecommunications wiretaps are commonly used by law enforcement in criminal investigations. While phone-based wiretapping has seen considerable success, the same cannot be said for Internet taps. Large portions of intercepted Internet traffic are often encrypted, making it difficult to obtain useful information. The advent of the Internet of Things further complicates network wiretapping. In fact, the current level of complexity of intercepted network traffic is almost at the point where data cannot be analyzed without the active involvement of experts. Additionally, investigations typically focus on analyzing traffic in chronological order and predominately examine the data content of the intercepted traffic. This approach is overly arduous when the amount of data to be analyzed is very large. This chapter describes a novel approach for analyzing large amounts of intercepted network traffic based on traffic metadata. The approach significantly reduces the analysis time and provides useful insights and information to non-technical investigators. The approach is evaluated using a large sample of network traffic data.
      16Scopus© Citations 6