1 / 32

Securing JPEG2000 (J2K) - The Next Generation Image Compression Standard

Securing JPEG2000 (J2K) - The Next Generation Image Compression Standard. Robert H. Deng, Yongdong Wu, Di Ma Institute for Infocomm Research Singapore. JPEG2000 (J2K) is an emerging standard for image compression

sammy
Download Presentation

Securing JPEG2000 (J2K) - The Next Generation Image Compression Standard

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Securing JPEG2000 (J2K)- The Next Generation Image Compression Standard Robert H. Deng, Yongdong Wu, Di Ma Institute for Infocomm Research Singapore

  2. JPEG2000 (J2K) is an emerging standard for image compression Achieves state-of-the-art low bit rate compression and has a rate distortion advantage over the original JPEG. Allows to extract various sub-images from a single compressed image codestream, the so called “Compress Once, Decompress Many Ways”. ISO/IEC JTC 29/WG1 Security Working Setup in 2002 Background

  3. By layers By resolutions Region of Interest “Compress Once, Decompress Many Ways” A Single Original Codestream

  4. Data Structure of J2K Image Codestreams The Authentication Scheme The Access Control Scheme Prototype Demo Outline

  5. Data Structure of J2K Image Codestreams

  6. Components • Each image is decomposed into one or more components, such as R, G, B. • Denote components as Ci, i = 1, 2, …, nC.

  7. Resolution & Resolution-Increments • J2K uses 2-D Discrete Wavelet • Transformation (DWT) 1-level DWT

  8. Resolution and Resolution-Increments 1-level DWT 2-level DWT

  9. Resolution and Resolution-Increments 2-level DWT Resolution 1 = {R0, R1} Resolution 0 = R0 Resolution 2 = {R0, R1, R2} Resolution-increments: R0 R1 R2

  10. Precincts Each resolution level is further partitioned into rectangular regions known as Precincts, Pi, i = 1, 2, …, nP

  11. Layers & Layer-Increments • J2K encodes quantized wavelet coeffieicnts from MSB bit-plane to LSB Bit-plane • Bit-planes are truncated some points. Data between two truncation points form a quality • layer-increment, • Li, i = 1, 2, …, nL LnL … L2 L1 L0

  12. Layers & Layer-Increments {L0, L1} {L0, L1, L2} L0 All layer- increments

  13. Packet (Cont.)

  14. A J2K codestream can be viewed as a set of series of packets; they are the most fundamental building blocks of a codestream. A packet is uniquely identified by four parameters C, R, P and L, all the packets in a codestream can be sorted with respect to these four parameters in some orders, called Progression Orders. There are five Progression Orders which are LRCP, RLCP, RPCL, CPRL and PCRL respectively. Packets & Progression Orders

  15. Progression Order Packets in a codestream with progression order LRCP:

  16. J2K Authentication

  17. Third-Party Publication Owner Client1 Image Source Signature + & SIT1 (Signing key) Client2 Signature A single codestream + signature Signature + & SIT3 Client3 3rd Party Publisher “Sign Once, Verify Many Ways”

  18. The Merkle Tree Sig(hr) Root hr hb ha A B h(n4) h(n1) h(n2) h(n3) n1 n2 n3 n4

  19. A Codestream Example 4 resolutions: R0, R1, R2, R3 2 layers: L0, L1 2 precincts: P0, P1

  20. R0 L0 L1 P1 P0 P1 P0 The Merkle Tree For the Example Root 2 1 R3 R1 R2 L0 L0 L1 L0 L1 L1 P0 P1 P0 P1 P1 P0 P1 P0 P1 P0 P1 P0 y1 y2 y3 y4 y5 y6 y7 y8 y9 y10 y11 y12 y13 y14 y15 y16 User asks for resolution 1, Publisher sends y1, …, y8, signed root, } SIT= { 2 1

  21. Resolution and Resolution-Increments 2-level DWT Resolution 1 = {R0, R1} Resolution 0 = R0 Resolution 2 = {R0, R1, R2} Resolution-increments: R0 R1 R2

  22. Layers & Layer-Increments {L0, L1} {L0, L1, L2} L0 All layer- increments

  23. L0 L0 L0 L0 L1 L1 L1 L1 P0 P1 P0 P1 P0 P1 P0 P1 P0 P1 P0 P1 P0 P1 P0 P1 The Optimized Merkle Tree Root R0 R1 R2 1 R3 y1 y2 y3 y4 y5 y6 y7 y8 y9 y10 y11 y12 y13 y14 y15 y16 User asks for resolution 1, Publisher sends y1, …, y8, signed root, SIT={ } 1 In J2K, max resolutions 33, max layers 65535

  24. J2K Access Control

  25. The Super-Distribution Model Key Server Publisher Encrypted Codestream Client1 Client2 Client3 “Encrypt Once, Decrypt Many Ways” Encrypt every packet will a different key? Too many keys are needed.

  26. A Codestream Example 3 resolutions: R0, R1, R2, 3 layers: L0, L1, L2 2 precincts: P0, P1

  27. Security Classes of Resolution-Increments R2 > R1 > R0 (total ordering) Security Classes of Layer-Increments L2 > L1 >L0 (total ordering) Security Classes of Precincts P1 and P0 are incomparable (i.e., isolated classes) Form combined hierarchy, the resulting lattice is a Directed Acyclic Graph, not a rooted tree! Security Classes in a Codestream

  28. Access Control Scheme 1 Master Key K kR2=h(k|R) kL2=h(k|L) kL1=h(kL2) kR1=h(kR2) kL0=h(kL1) kP0=h(k|P|0) kR0=h(kR1) kP1=h(k|P|1) Packet key: krlp=h(kRr|kLl|kPp), (1) for r = 0, 1, 2; l =0, 1, 2, p = 0, 1

  29. Encryption Owner generates a master key, and the packet keys for all the packets. Uses packet keys to encryption the corresponding packets. Distributes ciphertext to users. Decryption To access a sub-image, user requests intermediate keys from a server, derives packet keys to decrypt packets corresponding to the sub-image. Encryption & Decryption

  30. Collusion Attack • User1 & User2 collude, • kR2, kR0 kR2 • kL0, kL2 kL2 • kP0 & kP1 • Get resolution 2 & layer 2 • User1 asks resolution 2, layer 0, gets kR2, kL0, kP0, kP1 • User2 asks resolution 0, layer 2, gets kR0, kL2, kP0, kP1

  31. Assuming the preferred progression order is RLP Access Control Scheme 2 Root (master key) L0(k20) L2(k22) L1(k21) R2(k2) P1 (k201) P0 (k220) P1 (k221) P0 (k210) P0 (k200) P1 (k211) L0(k10) L2(k12) L1(k11) R1(k1) P1 (k101) P1 (k121) P1 (k111) P0 (k120) P0 (k110) P0 (k100) P0 L0(k00) L2(k02) L1(k01) R0 (k0) P1 (k001) P0 (k020) P1 (k021) P1 (k011) P0 (k010) P0 (k000)

  32. J2K codestream: “compress once, decompress many ways” Authentication scheme: “Sign once, Verify many ways” (has been incorporated in the standard document) Access Control scheme: “Encrypt once, Decrypt many ways” (under evaluation) Conclusions

More Related