There are many reasons to hide information but most common reason is to protect it from unauthorized access and people coming to know the existence of the secret information. In the corporate world audio data hiding can be used to hide and secure confidential chemical formulas or designs of new invention. Not only in commercial sector, it can also be used in used in the non-commercial sector to hide data that someone wants to keep private. Terrorists organization have been using audio data hiding since long time to keep their communications secret and to organize attacks. We are going to talk about confidential information hiding with the help of information and data security solutions expert.
Steganography is the science of hiding confidential information in a cover file so that only dispatcher and recipient know the existence of the confidential information. Confidential information is encoded in a way so that the very existence of the information is hidden. The main objective of steganography is to converse securely in a completely invisible mode and to shun drawing doubt to the communication of hidden information. Steganography not only prevents people from knowing about the hidden confidential information, but it also prevents others from thinking that somebody is communicating in a hidden way. If a steganography technique causes someone to believe there is hidden information in a carrier medium, then the technique has botched. The essential technique of audio steganography consists of Carrier (Audio file), Message and Password. Carrier file is also called as a cover-file, which hides the confidential information. Essentially, in steganography message is the information that the sender desires that it should remain confidential. Message can be image, plain text, audio or any type of file. Password is also called as a stego-key, and it assures that only the receiver who knows the password will be able to extract the confidential information or message from a cover-file. The cover-file with the confidential information is called as a stego-file.
The confidential information hiding procedure consists of subsequent two steps
Identification of redundant bits in the cover-file. Redundant bits are that bits that can he modified without corrupting the eminence or destroying the integrity of the cover-file.
To insert the confidential information in the cover file, the redundant bits in the cover file is interchanged by the bits of the confidential information.
AUDIO STEGANOGRAPHIC METHODS
Mike Stevens, information and data security training explains that there have been many approaches for hiding confidential information or messages in audio in such a manner that the changes made to the audio file are not visible. Common approaches are:
LSB (Least Significant Bit) approach is very famous approach and it replaces the least significant bit in some bytes of the cover file to conceal a sequence of bytes enclosing the hidden data. That's usually an effective approach in cases where the LSB substitution doesn't cause significant quality degradation, such as in 24-bit bitmaps. In computing, the least significant bit (LSB) is the bit position in a binary integer contributing the unit’s value, that is, controlling whether the number is even or odd. Using this approach you can hide a byte every eight bytes of the cover. There's a fifty percent chance that the bit you're substituting is the same as its replacement, in other words, half the time, the bit doesn't change, which helps to reduce quality degradation.
Parity coding is one of the most robust audio steganographic approach. In place of breaking a signal into individual samples, this approach breaks a signal into separate samples and inserts each bit of the confidential information from a parity bit. If the parity bit of a chosen region does not match the secret bit to be encoded, the procedure inverts the LSB of one of the samples in the region. Hence, the sender has different choices in encoding the secret bit.
The phase coding method works by switching the phase of an initial audio segment with a reference phase that symbolizes the confidential information. The persisting segments phase is changed in order to preserve the relative phase amid segments. In terms of signal to noise ratio, Phase coding is very effective coding approach. When there is a drastic change in the phase relation amid each frequency element, noticeable phase dispersion will happen. But, as long as the alteration of the phase is adequately small, an inaudible coding can be attained. This approach relies on the fact that the phase elements of sound are not as perceptible to the human ear as noise is says ethical hacking training professor.
The basic spread spectrum (SS) approach tries to spread confidential information through the frequency spectrum of the audio signal. This is like system, which uses logic of the LSB that spans the message bits unsystematically over the complete sound file. Nevertheless, dissimilar to LSB coding, the Spread Spectrum approach spreads the confidential information through the frequency spectrum of the sound file using a code, which is sovereign of the actual signal. Thus, the final signal captures a bandwidth, which is more than what is actually needed for transmission.
Echo hiding procedure inserts confidential information in a sound file by presenting an echo into the discrete signal. Echo hiding has benefits of delivering a high data transmission rate and higher robustness when competed to other methods. Only one bit of confidential information could be encoded if only one echo was created from the original signal. Therefore, before the encoding procedure begins the original signal is broken down into blocks. When the encoding procedure is done, the blocks are concatenated back together to deliver the final signal.
With the help of ethical hacking training organization professor of IICyberSecurity, we are going to see some software and mobile apps, which people can use to encode their messages and send hidden messages via email, social media or WhatsApp mobile phone.
Deep sound is audio stenography software for windows and can be use to create secret message via audio file. It is information security solutions freeware and supports all kinds of audio files.
Hide secret information into carrier audio file
To hide secret information into audio file, do the following steps:
Choose the carrier audio file and make sureits format is one of them flac, wav, wma, mp3, ape.
Click encode and the file will be encoded and then you can click 'Add files' to add secret files into the panel on the right side of application.
You can choose output audio format (wav, flac or ape). DeepSound does not support wma output format. If you desire to hide secret information into wma, hide secret information into wav file and then use external software such as Windows Media Encoder for change wav to wma lossless.
In the settings you can select to turn On/Off encrypting and set password. New audio file will be saved to the output directory. Select Ok to start hiding secret files into carrier audio file.
Extract secret data from audio file
As per information and data security solutions experts, to remove secret data from audio file, follow the following steps:
In the file explorer, choose the audio file, which encloses secret data. If the secret files are encrypted, input password.
DeepSound examines the selected file and exhibits secret files. Click the right mouse button and press F4 key or select extract secret files.
Open the Audio Converter.To add input files select 'Add files' button and the supported input audio formats are:
- Free Lossless Audio Codec (.flac)
- Windows media audio lossless (.wma)
- MPEG audio layer-3 (.mp3)
- Monkey's Audio (.ape)
Choose Output Format for the file and the supported output audio formats are:
- Waveform Audio File Format (.wav)
- Free Lossless Audio Codec (.flac)
- MPEG audio layer-3 (.mp3)
- Monkey's Audio (.ape)
You can learn more about DeepSound en information security training of International Institute of Cyber Security.
Hide It In
This app conceals an image taken with your iPhone camera into another apparently innocuous image from your photo library. Select the cover image and take any photo from your mobile phone. You can hide It In characters among other things, AES encryption to safeguard that even if the existence of a secret message is questioned, only the people with password can recover the hidden image.
Acostic Picture Transmitter
This app lets you transfer and accept images acoustically. To do this each column of the selected message gets altered by a Fast Fourier Transform and outputted across iPhones speaker. On the accepting iOS-device the received audio is envisioned by a spectrogram and the arriving images become visible. You can use this app for instance to transfer images very effortlessly over a phone or to put images in all kind of audio recording says information security solutions experts.
According to developer BlueJava, the Steg-O-Matic app hides the secret message in an image and offers tools for sending the image via email, social media or post it on a public blog. Only those intended to read the secret will know to look for it and know how to retrieve it. You can learn more about it during information security training.
DaVinci Secret Message
An Android app, DaVinci Secret Message can password shield the data hidden within an image, providing another level of security. It also provides the choice to delimit the size of the final image, thus making it more challenging to suspect whether a carrier image holds a secret based on its size alteration from the original image file.
This Android application uses both steganography and cryptography to hide diverse types of data such as text messages, pdf files, images, music files, etc. within images without altering the superficial appearance of the image. The experts of ethical hacking training endorses it for use by business individuals worried about competitors spying.