Introduction: In modern digital era, everyone who is part of digital ecosystem leaves digital footprints of their activities on various digital platforms. The same holds true for the wildlife criminals also. They are using digital gadgets & internet to commit wildlife crimes. In the process, they also leave digital footprints of their criminal activities which can be used by willdife law enforcement agencies as digital evidence against wildlife criminals in the court of law during trial to secure their conviction. These digital evidences may be admissible in the court of law only when their integrity and authennticity is unquestionable. Wwildlife crime investigators can use hash value to prove the integrity and authenticity of the digital evidences in the court of law.
What is Hash Value: A hash value is a fixed-length alphanumeric string that is generated using a mathematical algorithm like SHA-256 or MD5. This cryptographic output can be termed as a unique digital fingerprint for a given set of digital data. Two different sets of digital data can not have same hash value. In some ways the hash value of a digital file can be likened with human DNA. Just as every human being has a uniques sequence of DNA, every digital file has also unique hash value. DNA is used to identify the individual and hash value is used to verify the authenticity of digital files and to check if any tampering has been done. Both DNA & Hash Value are used in the court as evidence by the prosecutors against the criminals including wildlife traffickers.
Calculating Hash Value of Digital Files: Hash Value can be calculated for all types of files i.e. text file, word file, audio, video, pdf, ppt etc. Even a Folder containing several types of files or media storage of a digital device containing huge amount of digital data can also be selected for calculation of Hash Value. Digital Forensics Laboratories use various forensic tools like Cellibrite UFED to calculate the Hash Value of digital data contained in digital device using various cryptographic algorithms. There are also many open source Hash Value calculation tools available such as HashCalc(https://www.slavasoft.com/hashcalc/), QuickHash(https://www.quickhash-gui.org/), HashMyFiles(https://www.nirsoft.net/utils/hash_my_files.html) etc. Following is the example of calculation of Hash Value of several types of files using 'HashMyFiles' tool. This tool shows the Hash Value of a file using different cryptographic algorithms such as MD5, SHA1, CRC32, SHA-256, SHA-512 etc.
If any alteration (addition or deletion) is done in any digital file, it's hash value will change completely. Let me show it by calculating the hash value of same doc file i.e. TEST File.docx twice: once in its original form and then after adding just one additional comma (,) in this file. Let's see how two different hash value of same file is generated:
As is evident from the above that even a miniscule alteration in the file changes its hash value.
Significance of Hash Value in Wildlife Law Enforcement:
- Through hash value, wildlife crime investigator can ensure the integrity of digital evidences gathered during the investigation against the accused. Whenever the investigating officer obtains some digital file of evidentiary value, he should calculate the hash value and record it in the seizing documents in the presence of eye-witnesses. If the integrity and authenticity of that digital evidence is ever questioned by the defence counsel in the court of law accusing wildlife law enforcement officials of planting those incriminating evidences in the seized device at later stage to frame his client, it's hash value can be recalculated and can be compared with the original one. If both hash value match, it shows that no tampering with the evidence has been done and that evidence will be admissible in the court leading to conviction of the wildlife crime accused.
- Maintaining Chain of Custody is also very crucial in wildlife crime investigation. Hash Value can play instrumental role in it. Each time the seized digital devices change hands, their hash value can be recomputed and recorded to create a unbroken trail that shows who had access to the evidence and when. It also ensures the accountability on the part of the official under whose custody the evidence was there. If any tampering is done at any stage, that can easily be attributed to the individual official and responsibility can be fixed. This not only strengthens the credibility of digital evidence presened in the court but also uphold the integrity of the entire wildlife crime investigative process itself.
- Hashing of digital evidences can also ensure that data is not tampered during digital transmission to other stakeholders of wildlife criminal justice ecosystem such as defence lawyer, prosecutorial officers, judicial officers etc. Before sending sensitive informations to other agencies or experts, it can be hashed. Upon receiving of informations, the recipient can again hash it to see if any tampering has taken place during transmission or it is the original one by matching the two hash values.
- Hashing can also identify duplicate or similar files. In wildlife law enforcement, this may be important to establish connections between suspects of wildlife poaching or illegal wildlife trade. Identifying similar or duplicate files may also help in efficient data management by wildlife crime investigators. By comparing hash values duplicate files can easily be identified and removed streamlining the investigative process and conserving the valuable resources.
Conclusion: Hash Value or Cryptographic Fingerprints of digital evidences provide a robust mechanism to establish the authenticity and integrity of the digital evidences in ever-evolving landscape of wildlife law enforcement. It will not be an exaggeration to call Hash Value a formidable ally of wildlife crime investigator in ensuring that case against the wildlife criminals are proven beyond any reasonable doubt in the court of law during the trial and wildlife criminals are convicted for their crimes.