The Maharashtra Anti Corruption Bureau (ACB) has found a simple yet high tech solution to deal with allegations of tampering with evidence by the defense at trial stage.
ACB officials said every piece of evidence in each of their cases is now ‘digitised’ and each file is now assigned a software-generated serial number called ‘hash value’, which is recorded in the presence of witnesses. The hash value changes even if there is a minor change in the content of the file.
According to ACB officials, the decision was taken after it was observed that at trial stage, many cases suffer setbacks when the defense alleges that the panchnamas, witness statements, and audio or video recordings have been tampered with.
“We decided to digitise every piece of evidence, be it in the form of audio, video or text document. Every file is then passed through a software called Hash Value Generator, which assigns a hash value — a 66-digit serial number that contains the date and time of creation of the file. This hash value is then recorded in the presence of witnesses,” said Praveen Dixit, Director General, ACB.
Officials said that the hash value is sensitive to every change in the content of the file, and hence, no change can be made to the file after the hash value is assigned to it.
“For example, if I type out a panchnama and assign it a hash value, even the removal of a period will result in a change in the hash value,” said Additional Commissioner of Police Kishore Jadhav ACB, Mumbai.
Officials said that the hash value was proving useful in more ways than one. Apart from providing a defense against allegations of evidence tampering, it also certifies the evidence as authentic.
“The Information Technology Act dictates that every piece of digitised evidence be certified as authentic before it is presented in court, and the hash value is one of the ways in which such certification can be obtained. It makes the evidence foolproof,” Jadhav added.