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DCT Coefficient Manipulation

Definition

A transform-domain technique that embeds data in the discrete cosine transform coefficients of a JPEG block, operating within the compressed representation rather than raw pixel values.

Related terms

Carrier (Cover Object)
The original file, image, audio recording, or video clip used to conceal the hidden message. The modified version containing the hidden data...
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...
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...

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