While the conventional forensic scientists routinely validate and express the results of their investigations quantitatively using statistical measures from probability theory,digital forensics examiners rarely if eve...While the conventional forensic scientists routinely validate and express the results of their investigations quantitatively using statistical measures from probability theory,digital forensics examiners rarely if ever do so.In this paper,we review some of the quantitative tools and techniques which are available for use in digital forensic investigations,including Bayesian networks,complexity theory,information theory and probability theory,and indicate how they may be used to obtain likelihood ratios or odds ratios for the relative plausibility of alternative explanations for the creation of the recovered digital evidence.The potential benefits of such quantitative measures for modern digital forensics are also outlined.展开更多
The Enhanced Complexity Model( ECM) developed previously has been further extended to produce a Motivationally Enhanced Complexity Model( MECM) which enables the degree of motivation,capability and opportunity of a hy...The Enhanced Complexity Model( ECM) developed previously has been further extended to produce a Motivationally Enhanced Complexity Model( MECM) which enables the degree of motivation,capability and opportunity of a hypothetical Trojan Horse author to be included in quantifying the relative plausibility of competing explanations for the existence of uncontested digital evidence.This new model has been applied to the case of the Trojan Horse defence( THD) against the possession of child pornography.Our results demonstrate that the THD in this case cannot be plausibly sustained unless it can be shown that an ‘off-theshelf'( OTS) Trojan Horse for this task is available and it is not detectable by the target computer,at the material time.展开更多
文摘While the conventional forensic scientists routinely validate and express the results of their investigations quantitatively using statistical measures from probability theory,digital forensics examiners rarely if ever do so.In this paper,we review some of the quantitative tools and techniques which are available for use in digital forensic investigations,including Bayesian networks,complexity theory,information theory and probability theory,and indicate how they may be used to obtain likelihood ratios or odds ratios for the relative plausibility of alternative explanations for the creation of the recovered digital evidence.The potential benefits of such quantitative measures for modern digital forensics are also outlined.
文摘The Enhanced Complexity Model( ECM) developed previously has been further extended to produce a Motivationally Enhanced Complexity Model( MECM) which enables the degree of motivation,capability and opportunity of a hypothetical Trojan Horse author to be included in quantifying the relative plausibility of competing explanations for the existence of uncontested digital evidence.This new model has been applied to the case of the Trojan Horse defence( THD) against the possession of child pornography.Our results demonstrate that the THD in this case cannot be plausibly sustained unless it can be shown that an ‘off-theshelf'( OTS) Trojan Horse for this task is available and it is not detectable by the target computer,at the material time.
