Vincent van der Meer , Jeroen van den Bos , Hugo Jonker , Laurent Dassen
{"title":"Problem solved: A reliable, deterministic method for JPEG fragmentation point detection","authors":"Vincent van der Meer , Jeroen van den Bos , Hugo Jonker , Laurent Dassen","doi":"10.1016/j.fsidi.2023.301687","DOIUrl":null,"url":null,"abstract":"<div><p>Recovery of deleted JPEG files is severely hindered by fragmentation. Current state-of-the-art JPEG file recovery methods rely on content-based approaches. That is, they consider whether a sequence of bytes translates into a consistent picture based on its visual representation, treating fragmentation indirectly, with varying results. In contrast, in this paper, we focus on identifying fragmentation points on bit-level, that is, identifying whether a candidate next block of bytes is a valid extension of the current JPEG. Concretely, we extend, implement and exhaustively test a novel deterministic algorithm for finding fragmentation points in JPEGs. Even in the worst case scenario, our implementation finds over 99.4 % of fragmentation points within 4 kB – i.e., within the standard block size on NTFS and exFAT file systems. As such, we consider the problem of detecting JPEG fragmentation points solved.</p></div>","PeriodicalId":48481,"journal":{"name":"Forensic Science International-Digital Investigation","volume":null,"pages":null},"PeriodicalIF":2.0000,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666281723002068/pdfft?md5=cd50e080cf971349294eddc303a4a864&pid=1-s2.0-S2666281723002068-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Forensic Science International-Digital Investigation","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2666281723002068","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"COMPUTER SCIENCE, INFORMATION SYSTEMS","Score":null,"Total":0}
引用次数: 0
Abstract
Recovery of deleted JPEG files is severely hindered by fragmentation. Current state-of-the-art JPEG file recovery methods rely on content-based approaches. That is, they consider whether a sequence of bytes translates into a consistent picture based on its visual representation, treating fragmentation indirectly, with varying results. In contrast, in this paper, we focus on identifying fragmentation points on bit-level, that is, identifying whether a candidate next block of bytes is a valid extension of the current JPEG. Concretely, we extend, implement and exhaustively test a novel deterministic algorithm for finding fragmentation points in JPEGs. Even in the worst case scenario, our implementation finds over 99.4 % of fragmentation points within 4 kB – i.e., within the standard block size on NTFS and exFAT file systems. As such, we consider the problem of detecting JPEG fragmentation points solved.