Optical cryptanalysis is essential to the further investigation of more secure optical cryptosystems.Learning-based at-tack of optical encryption eliminates the need for the retrieval of random phase keys of optical e...Optical cryptanalysis is essential to the further investigation of more secure optical cryptosystems.Learning-based at-tack of optical encryption eliminates the need for the retrieval of random phase keys of optical encryption systems but it is limited for practical applications since it requires a large set of plaintext-ciphertext pairs for the cryptosystem to be at-tacked.Here,we propose a two-step deep learning strategy for ciphertext-only attack(COA)on the classical double ran-dom phase encryption(DRPE).Specifically,we construct a virtual DRPE system to gather the training data.Besides,we divide the inverse problem in COA into two more specific inverse problems and employ two deep neural networks(DNNs)to respectively learn the removal of speckle noise in the autocorrelation domain and the de-correlation operation to retrieve the plaintext image.With these two trained DNNs at hand,we show that the plaintext can be predicted in real-time from an unknown ciphertext alone.The proposed learning-based COA method dispenses with not only the retrieval of random phase keys but also the invasive data acquisition of plaintext-ciphertext pairs in the DPRE system.Numerical simulations and optical experiments demonstrate the feasibility and effectiveness of the proposed learning-based COA method.展开更多
As a candidate of the standard of post-quantum cryptography for NIST,Liu,et al.submitted a new public-key encryption scheme Compact-LWE,whose structure is similar to LWE,but with different distribution of errors.They ...As a candidate of the standard of post-quantum cryptography for NIST,Liu,et al.submitted a new public-key encryption scheme Compact-LWE,whose structure is similar to LWE,but with different distribution of errors.They thought that the special error distribution would protect Compact-LWE from known lattice-based attacks.Furthermore,they recommended a set of small parameters to improve the efficiency of Compact-LWE and claimed it can offer 192-bit security.However,in this paper,the authors show that Compact-LWE is not secure under recommended parameters by presenting two ciphertext-only attacks.First,the authors show that the message can be recovered efficiently from the ciphertext.Then the authors go further to recover an equivalent private key efficiently from the public key by exploiting the special structure of Compact-LWE.展开更多
基金financial supports from the National Natural Science Foundation of China(NSFC)(62061136005,61705141,61805152,61875129,61701321)Sino-German Research Collaboration Group(GZ 1391)+2 种基金the Mobility program(M-0044)sponsored by the Sino-German CenterChinese Academy of Sciences(QYZDB-SSW-JSC002)Science and Technology Innovation Commission of Shenzhen(JCYJ20170817095047279)。
文摘Optical cryptanalysis is essential to the further investigation of more secure optical cryptosystems.Learning-based at-tack of optical encryption eliminates the need for the retrieval of random phase keys of optical encryption systems but it is limited for practical applications since it requires a large set of plaintext-ciphertext pairs for the cryptosystem to be at-tacked.Here,we propose a two-step deep learning strategy for ciphertext-only attack(COA)on the classical double ran-dom phase encryption(DRPE).Specifically,we construct a virtual DRPE system to gather the training data.Besides,we divide the inverse problem in COA into two more specific inverse problems and employ two deep neural networks(DNNs)to respectively learn the removal of speckle noise in the autocorrelation domain and the de-correlation operation to retrieve the plaintext image.With these two trained DNNs at hand,we show that the plaintext can be predicted in real-time from an unknown ciphertext alone.The proposed learning-based COA method dispenses with not only the retrieval of random phase keys but also the invasive data acquisition of plaintext-ciphertext pairs in the DPRE system.Numerical simulations and optical experiments demonstrate the feasibility and effectiveness of the proposed learning-based COA method.
基金supported by the National Natural Science Foundation of China under Grant No.61572490the National Key Research and Development Project under Grant No.2018YFA0704705the National Center for Mathematics and Interdisciplinary Sciences,CAS。
文摘As a candidate of the standard of post-quantum cryptography for NIST,Liu,et al.submitted a new public-key encryption scheme Compact-LWE,whose structure is similar to LWE,but with different distribution of errors.They thought that the special error distribution would protect Compact-LWE from known lattice-based attacks.Furthermore,they recommended a set of small parameters to improve the efficiency of Compact-LWE and claimed it can offer 192-bit security.However,in this paper,the authors show that Compact-LWE is not secure under recommended parameters by presenting two ciphertext-only attacks.First,the authors show that the message can be recovered efficiently from the ciphertext.Then the authors go further to recover an equivalent private key efficiently from the public key by exploiting the special structure of Compact-LWE.
