  Cryptography is the study of securing information. It is the physical process
that scrambles the information by rearrangement and substitution of content, so
that it becomes difficult for anyone to understand. In today's world, security
has become an inevitable part of our day-to-day life, right from normal
browsing to performing critical payment transactions. Hackers work endlessly to
break the security present in the apps/websites on which we perform day-to-day
operations and salvage valuable information. Because of this, many illegal
activities have taken place which affect the user. One such illegal activity is
tapping the voice communication between two users. If left unencrypted, the
communication between the users is compromised, thereby causing issues. One way
to prevent this act is to encrypt the audio in that the contents cannot have
tampered with unless the receiver has the valid key to decrypt it. The proposed
solution termed "HexE" aims to create a puzzle-based algorithm which would
encrypt and decrypt the audio files without manipulating the file header, thus
securing the contents. The algorithm works on an NxN SuDoKu-based puzzle which
is accepted both by the sender and receiver. Using the timestamp of the event
(UNIX based), a grid from the puzzle is chosen which in turn will act as the
key for both encryption and decryption. If the timestamp is slightly adjusted,
the process will end up in failure during decryption, thus ensuring
confidentiality. Another approach to secure the audio files is to implement
IPFS (Inter Planetary File System) alongside the puzzle algorithm in which the
encrypted audio is stored on it and the receiver can fetch the audio provided
if the valid IPFS Hash of the file is present. In this way, the audio file is
secured.
