Carrier (Cover Object)
Definition
The original file, image, audio recording, or video clip used to conceal the hidden message. The modified version containing the hidden data is called the stego object.
- Role
- Original, unmodified file used to hide data
- Formats
- Image, audio or video files
- Result after embedding
- Called the stego object
- Field
- Steganography
Common questions
How does an examiner tell a carrier apart from a stego object once data is hidden?+
The stego object usually shows statistical deviations from the expected file structure, such as altered least-significant-bit distributions or file size anomalies, that steganalysis tools can flag even when no visual difference is apparent.
Does the choice of carrier affect how much data can be hidden?+
Yes, a carrier's file size, compression scheme and bit depth set a practical capacity limit, and embedding beyond that limit tends to introduce visible or statistically detectable artefacts that undermine the concealment.
Related terms
- Covert Channel
- Any communication path that was not intended by the system designer and that bypasses access-control or monitoring policies. Network covert channels are...
- DCT Coefficient Manipulation
- A transform-domain technique that embeds data in the discrete cosine transform coefficients of a JPEG block, operating within the compressed representation rather...
- LSB Substitution
- Least-significant-bit substitution: the lowest-order bit of each sample value (pixel colour channel or audio sample) is overwritten with one bit of the...
- Payload
- The action the malware performs once active: data encryption (ransomware), credential theft (banking trojan), resource hijacking (cryptominer), or system destruction (wiper). The...
- Steganography
- Concealing one file inside another in a way that hides the existence of the hidden file. LSB image manipulation, JPEG DCT coefficient...