Maintaining a clear and thorough chain of custody records is an essential part of the forensic examination process to prove the validity of digital evidence. Chain of custody refers to comprehensively documenting everyone who handled the evidence, what was done with it, and when, from initial acquisition through analysis and reporting.
In the case of Financial Services Inc., establishing an accurate chain of custody was crucial for ensuring the integrity and admissibility of the forensic image copied from the employee’s drive as part of the internal investigation. Their security team first created the duplicate file, calculated MD5 and SHA-1 hash values, recorded computer details, and sealed the image for transfer to Excellence Forensic LLC (Elgohary et al., 2022). Our examiner then continued the chain upon receipt by photographing the sealed package, generating new hashes when cloning data, and logging every access, transfer, and processing step. The start-to-finish time-stamped custody record lists all people handling the forensic image. It shows that the image’s realness stays whole. This satisfies legal norms.
Initial Collection
Financial Services Inc.’s security team duplicated an employee’s computer drive. They used FTK Imager software to make an exact forensic copy. This first imaging of the drive copied all contents precisely. It marked the start of evidence handling. Next, the team generated MD5 and SHA-1 hash values. These digitally fingerprinted the image file for later checks. Recording these details began a chain of custody documentation. Securing the copy also started the custody trail. This evidence tracking is vital from collection through analysis. It ensures integrity for the duplicated employee computer data (Elgohary et al., 2022).
Hash Generation
Financial Services Inc.’s security team finished forensically imaging the employee’s computer drive. They generated Message Digest 5 (MD5) and Secure Hash Algorithm first version (SHA-1) hash values next. These hashes digitally fingerprint the duplicated file. The fingerprints uniquely sign the new SSD.E01 image created. They allow verifying later when the file stays unaltered and uncorrupted. This confirms integrity as the investigation proceeds. The hashes let systems flag any changes to the evidentiary image. So, they help ensure that analysis draws solely on original replicated data from the worker’s device.
Documentation
Additionally, the team documented the computer make, model, and serial number. They logged imaging software used and time stamps, too. This source context links physical hardware to SSD.E01’s forensic image (Elgohary et al., 2022). It gives essential details for examination. Logging the initial duplication meets two custody goals. First, it creates integrity hashes to verify later. Second, it collects technical specifics on imaging. This establishes evidence provenance fully. Comprehensive documentation at the start achieves both these chain aims. It enables authentication checks afterward. Plus, it provides imaging process specifics. Together, these prove file reliability and history, which are crucial for admissibility.
Transfer to Excellence Forensic LLC
Financial Services Inc.’s internal security group officially passed custody of the copied forensic photo to Excellence Forensic LLC (Burri et al., 2020). Excellence Forensic would independently analyze external Financial Services. Following chain rules, internal security submitted needed evidence. This kept integrity whole. The hand-over between companies lets Excellence’s forensic specialists securely get the saved file. This file had the bit-for-bit drive duplicate from the employee. By correctly transferring custody between parties, the critical forensic data reached Excellence’s experts safely. There, it could undergo its outside review while complying with chain principles.
Sealed Packaging
First, Financial Services Inc.’s internal group sealed file SSD.E01. They also closed its hashes and imaging documents. Special tamper-proof packing was used. This packing prevented unwanted changes or entries when sent to Excellence Forensic LLC (Burri et al., 2020). Sealing the proofs carefully inside shielded wraps kept them secure. It maintained the chain history. The packing safeguarded the bundle as it left Financial Services Inc. It stayed guarded on the way to Excellence’s lab. This upheld trust in examination by Excellence Forensic later. It ensured that when Excellence received the package, fidelity remained intact. So, Excellence could proceed knowing the shipped forensic data and notes avoided meddling in transit. Correct safeguards were followed top-to-bottom per the rules.
Verification of Integrity
Upon receipt from Financial Services Inc., Excellence’s reviewer checked the package’s integrity. They thoroughly inspected the tamper seals for unauthorized access during shipping. Finding the bundle secure, the examiner created MD5 and SHA-1 hashes for the submitted file SSD.E01 (Burri et al., 2020). By matching these to Financial Services Inc.’s original hashes from the start of the duplication, the examiner proved the data stayed unaltered and undamaged.
Cloning Process
After checking that the integrity aligned with the chain form, the reviewer copied SSD.E01 exactly. The new file was named CLONE_SSD.E01 and was on a different outside drive (Patil et al., 2024). Duplicating the data this way permitted probing the contents without endangering the first photo file. Safeguarding the initial submission was vital for preservation. Inspecting the cloned version eased data workflows. This working forensic replica served as a “master proof piece.” It shielded case integrity long-range. Having a clone as the analysis master evidence item kept the originals in pristine, unopened condition. This maintains submissions as tamper-free permanent records while their mimics handle processing tasks.
Hash Verification
Per norms, the reviewer then made new hash values for CLONE_SSD.E01. This ensured copy accuracy and trustworthiness. Calculating updated MD5 and SHA-1 signs for the mimic and logging on the chain form guaranteed no loss in cloning (Patil et al., 2024). Equaling the clone’s hashes showed its ideal integrity as an exact bit-for-bit proof file. It stood prepared for inspection and reporting. The examiner verified precision by writing the duplicate’s fresh fingerprints and checking equivalence. The cloned submission matched the original down to the last bit. This conformity across old and new hashes validated CLONE_SSD.E01’s fitness. It could now undergo scrutiny, backed by records showing no distortion occurred through replication.
Analysis Phase
The reviewer processed and searched the cloned photo CLONE_SSD.E01 employing EnCase Forensic. EnCase is a trusted software for digital probes (Patil et al., 2024). It enabled thoroughly combing the mimicked drive to uncover proofs yet shield the original entries. EnCase permitted digging into CLONE_SSD.E01 to extract evidence without disturbing SSD.E01’s intact data. The chain shape was refreshed throughout. Everything done during the inspection was logged on the form. Every handling while screening and delving into the clone was documented. This traced continuity – who did what when to the mimic as it underwent scrutiny. Updating the custody record safeguarded history, demonstrating how CLONE_SSD.E01 was managed under examiner custody.
Ongoing Documentation
All related finds, extracted items, or inspection steps were meticulously added too. These joined the final inspection report on the chain form. Maintaining this thorough time-stamped record caught the full transparent analysis flow. At the same time, it tied reported proofs to the first photo file. Keeping detailed chronicles this way did two things simultaneously. All analytical doings were logged step-by-step as they happened. Plus, that trail, now stretched unbroken from results, returned the way to SSD.E01’s opening hashes. So observers can trace any evidence from finish to start: Validate discoveries against the baseline mimic. Then, confirm that the clone itself matches SSD.E01 via the custody trail. By reporting while recording, the analysis gains accountability.
By stressing strict chain rules, Financial Services Inc. and Excellence Forensic LLC show a pledge to digital proof clarity and merit. Thoroughly logging all managing, custody handoffs, and probe acts boosts results in integrity. Closely following record guidelines to get complete accuracy upholds moral norms in confidential studies. It satisfies lawful duties, too, if queries or fights occur later. This chain method indicates expert codes guarding sensitive worth and facts. Painstaking handling forms, precise descriptions, and checks along the way become shields. They defend purity for business and legal needs by acting as careful, repetitive records. This joint model proves authenticity origin-to-end, demonstrating the two groups’ good faith in proper, ethical, discreet analysis conduct.
References
Burri, X., Casey, E., Bollé, T., & Jaquet-Chiffelle, D.-O. (2020). Chronological independently verifiable electronic chain of custody ledger using blockchain technology. Forensic Science International: Digital Investigation, 33, 300976. https://doi.org/10.1016/j.fsidi.2020.300976
Elgohary, H. M., Darwish, S. M., & Elkaffas, S. M. (2022). Improving Uncertainty in Chain of Custody for Image Forensics Investigation Applications. IEEE Access, 10, 14669–14679. https://doi.org/10.1109/access.2022.3147809
Patil, H., Ravshish Kaur Kohli, Puri, S., & Puri, P. (2024). Potential applicability of blockchain technology in maintaining chain of custody in forensic casework. Egyptian Journal of Forensic Sciences, 14(1). https://doi.org/10.1186/s41935-023-00383-w
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