• Title/Summary/Keyword: partial encryption

Search Result 59, Processing Time 0.028 seconds

Selectively Partial Encryption of Images in Wavelet Domain (웨이블릿 영역에서의 선택적 부분 영상 암호화)

  • ;Dujit Dey
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.28 no.6C
    • /
    • pp.648-658
    • /
    • 2003
  • As the usage of image/video contents increase, a security problem for the payed image data or the ones requiring confidentiality is raised. This paper proposed an image encryption methodology to hide the image information. The target data of it is the result from quantization in wavelet domain. This method encrypts only part of the image data rather than the whole data of the original image, in which three types of data selection methodologies were involved. First, by using the fact that the wavelet transform decomposes the original image into frequency sub-bands, only some of the frequency sub-bands were included in encryption to make the resulting image unrecognizable. In the data to represent each pixel, only MSBs were taken for encryption. Finally, pixels to be encrypted in a specific sub-band were selected randomly by using LFSR(Linear Feedback Shift Register). Part of the key for encryption was used for the seed value of LFSR and in selecting the parallel output bits of the LFSR for random selection so that the strength of encryption algorithm increased. The experiments have been performed with the proposed methods implemented in software for about 500 images, from which the result showed that only about 1/1000 amount of data to the original image can obtain the encryption effect not to recognize the original image. Consequently, we are sure that the proposed are efficient image encryption methods to acquire the high encryption effect with small amount of encryption. Also, in this paper, several encryption scheme according to the selection of the sub-bands and the number of bits from LFSR outputs for pixel selection have been proposed, and it has been shown that there exits a relation of trade-off between the execution time and the effect of the encryption. It means that the proposed methods can be selectively used according to the application areas. Also, because the proposed methods are performed in the application layer, they are expected to be a good solution for the end-to-end security problem, which is appearing as one of the important problems in the networks with both wired and wireless sections.

A Study of Partial Preview Control Method of ePUB-based eBook DRM (ePUB 기반 전자책 DRM의 부분열람 제어 방법에 관한 연구)

  • Kim, Eun-Bum;Kim, Kyung-Il;Kim, Tae-Hyun;Cho, Seong-Hwan
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.12 no.1
    • /
    • pp.249-256
    • /
    • 2012
  • ePUB is one of the most pervasive eBook formats since it was announced as a 2009 standard in IDPF(International Digital Publishing Forum). ePUB is compressed as a ZIP Archive format and structured as a standard format of OCF. Domestically and internationally, eBook services applying DRM into ePUB have currently been active, while it does not satisfy various needs from business because it does not support preview service which is due to the encryption of the whole ePUB as a single key. This study suggests a way to apply diverse business models by providing eBook content based on ePUB multiple key encryption method, not by encrypting it simply as a single key. The encryption method which applies a multiple key encryption method is suggested as a practically appliable form together with licence issuing and delivery method and decryption method in eBook readers. The multiple key encryption method suggested in this study will make it possible to support partial preview services of ePUB based eBook content. It will be applied to diverse service models and enhance the security level better then single key based encryption method.

An Adaptive Information Hiding Technique of JPEG2000-based Image using Chaotic System (카오스 시스템을 이용한 JPEG2000-기반 영상의 적응적 정보 은닉 기술)

  • 김수민;서영호;김동욱
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.41 no.4
    • /
    • pp.9-21
    • /
    • 2004
  • In this paper, we proposed the image hiding method which decreases calculation amount by encrypt partial data using discrete wavelet transform and linear scale quantization which were adopted as the main technique for frequency transform in JPEG2000 standard. Also we used the chaotic system which has smaller calculation amount than other encryption algorithms and then dramatically decreased calculation amount. This method operates encryption process between quantization and entropy coding for preserving compression ratio of images and uses the subband selection method and the random changing method using the chaotic system. For ciphering the quantization index we use a novel image encryption algerian of cyclically shifted in the right or left direction and encrypts two quantization assignment method (Top-down/Reflection code), made change of data less. Also, suggested encryption method to JPEG2000 progressive transmission. The experiments have been performed with the proposed methods implemented in software for about 500 images. consequently, we are sure that the proposed are efficient image encryption methods to acquire the high encryption effect with small amount of encryption. It has been shown that there exits a relation of trade-off between the execution time and the effect of the encryption. It means that the proposed methods can be selectively used according to the application areas. Also, because the proposed methods are performed in the application layer, they are expected to be a good solution for the end-to-end security problem, which is appearing as one of the important problems in the networks with both wired and wireless sections.

Ciphering Scheme and Hardware Implementation for MPEG-based Image/Video Security (DCT-기반 영상/비디오 보안을 위한 암호화 기법 및 하드웨어 구현)

  • Park Sung-Ho;Choi Hyun-Jun;Seo Young-Ho;Kim Dong-Wook
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.42 no.2 s.302
    • /
    • pp.27-36
    • /
    • 2005
  • This thesis proposed an effective encryption method for the DCT-based image/video contents and made it possible to operate in a high speed by implementing it as an optimized hardware. By considering the increase in the amount of the calculation in the image/video compression, reconstruction and encryption, an partial encryption was performed, in which only the important information (DC and DPCM coefficients) were selected as the data to be encrypted. As the result, the encryption cost decreased when all the original image was encrypted. As the encryption algorithm one of the multi-mode AES, DES, or SEED can be used. The proposed encryption method was implemented in software to be experimented with TM-5 for about 1,000 test images. From the result, it was verified that to induce the original image from the encrypted one is not possible. At that situation, the decrease in compression ratio was only $1.6\%$. The hardware encryption system implemented in Verilog-HDL was synthesized to find the gate-level circuit in the SynopsysTM design compiler with the Hynix $0.25{\mu}m$ CMOS Phantom-cell library. Timing simulation was performed by Verilog-XL from CadenceTM, which resulted in the stable operation in the frequency above 100MHz. Accordingly, the proposed encryption method and the implemented hardware are expected to be effectively used as a good solution for the end-to-end security which is considered as one of the important problems.

A Encryption Technique of JPEG2000 Image Using 3-Dimensional Chaotic Cat Map (3차원 카오스 캣맵을 이용한 JPEG2000 영상의 암호화 기술)

  • Choi, Hyun-Jun;Kim, Soo-Min;Seo, Young-Ho;Kim, Dong-Wook
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.42 no.5 s.305
    • /
    • pp.173-180
    • /
    • 2005
  • In this paper, we proposed the image hiding method which decreases calculation amount by encrypt partial data using discrete wavelet transform(DWT) and linear scale quantization which were adopted as the main technique for frequency transform in JPEG2000 standard. Also we used the chaotic system and cat map which has smaller calculation amount than other encryption algorithms and then dramatically decreased calculation amount. This method operates encryption process between quantization and entropy coding for preserving compression ratio of images and uses the subband selection method. Also, suggested encryption method to JPEG2000 progressive transmission. The experiments have been performed with the Proposed methods implemented in software for about 500 images. Consequently, we are sure that the proposed is efficient image encryption methods to acquire the high encryption effect with small amount of encryption. It has been shown that there exits a relation of trade-off between the execution time and the effect of the encryption. It means that the proposed methods can be selectively used according to the application areas.

Certificateless Public Key Encryption Revisited: Security Model and Construction (무인증서 공개키 암호 기법의 재고: 안전성 모델 및 설계)

  • Kim, Songyi;Park, Seunghwan;Lee, Kwangsu
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.20 no.6
    • /
    • pp.1109-1122
    • /
    • 2016
  • Certificateless public key cryptography is a technique that can solve the certificate management problem of a public key cryptosystem and clear the key escrow issue of ID-based cryptography using the public key in user ID. Although the studies were actively in progress, many existing schemes have been designed without taking into account the safety of the secret value with the decryption key exposure attacks. If previous secret values and decryption keys are exposed after replacing public key, a valid private key can be calculated by obtaining the partial private key corresponding to user's ID. In this paper, we propose a new security model which ensures the security against the key exposure attacks and show that several certificateless public key encryption schemes are insecure in the proposed security model. In addition, we design a certificateless public key encryption scheme to be secure in the proposed security model and prove it based on the DBDH(Decisional Bilinear Diffie-Hellman) assumption.

Hardware Implementation of Chaotic System for Security of JPEG2000 (JPEG2000의 보안을 위한 카오스 시스템의 하드웨어 구현)

  • Seo Young-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.30 no.12C
    • /
    • pp.1193-1200
    • /
    • 2005
  • In this paper, we proposed an image hiding method which decreases the amount of calculation encrypting partial data rather than the whole image data using a discrete wavelet transform and a linear scalar quantization which have been adopted as the main technique in JPEG2000 standard and then implemented the proposed algorithm to hardware. A chaotic system was used instead of encryption algorithms to reduce further amount of calculation. It uses a method of random changing method using the chaotic system of the data in a selected subband. For ciphering the quantization index it uses a novel image encryption algorithm of cyclical shifting to the right or left direction and encrypts two quantization assignment method (Top-down coding and Reflection coding), made change of data less. The experiments have been performed with the proposed methods implemented in software for about 500 images. The hardware encryption system was synthesized to find the gate-level circuit with the Samsung $0.35{\mu}m$ Phantom-cell library and timing simulation was performed, which resulted in the stable operation in the frequency above 100MHz.

Partial Encryption in DWT Domain of Depth-map (깊이정보의 DWT 영역에서의 부분 암호화)

  • Ha, Jun;Choi, Hyun-Jun
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • 2012.11a
    • /
    • pp.108-109
    • /
    • 2012
  • 멀티미디어 콘텐츠이 사용이 급증함에 따라 유료 및 비밀유지를 필요로 하는 영상 데이터에 대한 보안문제가 중요시 되고 있다. 본 논문에서는 깊이정보(depth-map) 데이트를 숨기기 위한 깊이정보 영상 암호화 방식을 제안하였다. 이 기법은 깊이정보를 대상으로 웨이블릿 변환을 수행하여 깊이정보의 전체 데이터가 아닌 부분데이터를 암호화하는 방식을 사용하였다. 실험 결과 제안한 방식으로 깊이정보를 암호화 할 경우 전체 데이터량의 0.048%만을 암호화하여 깊이정보를 효과적으로 은닉할 수 있음을 확인하였다.

  • PDF

A Study on Partial Encryption DRM System for Random Symmetric Key (랜덤 대칭키를 이용한 부분 암호화 DRM 시스템에 관한 연구)

  • Jun, Woo-Jin
    • Proceedings of the KAIS Fall Conference
    • /
    • 2010.05a
    • /
    • pp.285-288
    • /
    • 2010
  • 본 논문에서는 기존의 암호화 방법보다 다양한 키를 생성하는 알고리즘을 제안하고, 키 생성 알고리즘을 통해 각각 생성된 대칭키를 서버에 저장하지 않는 기존의 시스템보다 보안성이 높은 암호화 방법을 제안한다. 제안한 시스템을 설계하고 구현한 후 성능 평가를 위해 다양한 크기의 비디오 데이터 파일을 이용하여 실험을 수행하여 제안한 시스템이 기존 시스템에 비해 비디오 데이터 파일 재생 시 암호화 복호화 시간을 포함한 지연시간을 줄어 든 것을 검증하였다.

  • PDF

PARTIAL KEY EXPOSURE ATTACKS ON RSA AND ITS VARIANT BY GUESSING A FEW BITS OF ONE OF THE PRIME FACTORS

  • Sarkar, Santanu;Maitra, Subhamoy
    • Bulletin of the Korean Mathematical Society
    • /
    • v.46 no.4
    • /
    • pp.721-741
    • /
    • 2009
  • Consider RSA with N = pq, q < p < 2q, public encryption exponent e and private decryption exponent d. We first study cryptanalysis of RSA when certain amount of the Most Significant Bits (MSBs) or Least Significant Bits (LSBs) of d is known. The basic lattice based technique is similar to that of Ernst et al. in Eurocrypt 2005. However, our idea of guessing a few MSBs of the secret prime p substantially reduces the requirement of MSBs or LSBs of d for the key exposure attack. Further, we consider the RSA variant proposed by Sun and Yang in PKC 2005 and show that the partial key exposure attack works significantly on this variant.