Recompression of JPEG crypto-compressed images without a key

Vincent Itier 1 Pauline Puteaux 1 William Puech 1
1 ICAR - Image & Interaction
LIRMM - Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier
Abstract : The rising popularity of social networks and cloud computing has greatly increased number of JPEG compressed image exchanges. In this context, the security of the transmission channel and/or the cloud storage can be susceptible to privacy leaks. Selective encryption is an efficient tool to mask image content and to protect confidentiality while remaining format-compliant. However, image processing in the encrypted domain is not a trivial task. In this work, we present a JPEG crypto-compression method which allows us to recompress a JPEG crypto-compressed image several times, without any information about the secret key or the original image content. Indeed, using the proposed method in this paper, each recompression can be done directly on the JPEG bitstream by removing the last bit of the code representation of each non-zero coefficient, adapting the entropic code part, and slightly modifying the quantization table. This method is efficient to recompress JPEG crypto-compressed images in terms of ratio compression. Moreover, the decryption of the recompressed image produces an image with a very similar visual quality when compared to the original image, according to the obtained results. Index Terms-JPEG compression, selective image encryption, image security, signal processing in the encrypted domain, recompression.
Document type :
Journal articles
Complete list of metadatas

Cited literature [51 references]  Display  Hide  Download

https://hal-lirmm.ccsd.cnrs.fr/lirmm-02023980
Contributor : William Puech <>
Submitted on : Monday, February 18, 2019 - 6:24:56 PM
Last modification on : Tuesday, February 19, 2019 - 1:22:30 AM
Long-term archiving on: Sunday, May 19, 2019 - 7:24:17 PM

File

08624571.pdf
Publisher files allowed on an open archive

Identifiers

Collections

Citation

Vincent Itier, Pauline Puteaux, William Puech. Recompression of JPEG crypto-compressed images without a key. IEEE Transactions on Circuits and Systems for Video Technology, Institute of Electrical and Electronics Engineers, In press, ⟨10.1109/tcsvt.2019.2894520⟩. ⟨lirmm-02023980⟩

Share

Metrics

Record views

115

Files downloads

91