## CryptoDB

### Dengguo Feng

#### Publications

Year
Venue
Title
2018
JOFC
2015
EPRINT
2015
EPRINT
2014
EPRINT
2014
EPRINT
2014
EPRINT
2014
EPRINT
2014
EPRINT
2014
EPRINT
2014
EPRINT
2013
CRYPTO
2013
FSE
2012
FSE
2011
ASIACRYPT
2010
ASIACRYPT
2008
EPRINT
LUX is a new hash function submitted to NIST's SHA-3 competition. In this paper, we found some non-random properties of LUX due to the weakness of origin shift vector. We also give reduced blank round collision attack, free-start collision attack and free-start preimage attack on LUX-256. The two collision attacks are trivial. The free-start preimage attack has complexity of about 2^80 and requires negligible memory.
2008
EPRINT
Since the first collision differential with its full differential path was presented for MD5 function by Wang et al. in 2004, renewed interests on collision attacks for the MD family of hash functions have surged over the world of cryptology. To date, however, no cryptanalyst can give a second computationally feasible collision differential for MD5 with its full differential path, even no improved differential paths based on Wangs MD5 collision differential have appeared in literature. Firstly in this paper, a new differential cryptanalysis called signed difference is defined, and some principles or recipes on finding collision differentials and designing differential paths are proposed, the signed difference generation or elimination rules which are implicit in the auxiliary functions, are derived. Then, based on these newly found properties and rules, this paper comes up with a new computationally feasible collision differential for MD5 with its full differential path, which is simpler thus more understandable than Wangs, and a set of sufficient conditions considering carries that guarantees a full collision is derived from the full differential path. Finally, a multi-message modification-based fast collision attack algorithm for searching collision messages is specialized for the full differential path, resulting in a computational complexity of 2 to the power of 36 and 2 to the power of 32 MD5 operations, respectively for the first and second blocks. As for examples, two collision message pairs with different first blocks are obtained.
2008
EPRINT
Side-channel attacks are a very powerful cryptanalytic technique. Li and Gu [ProvSec'07] proposed an approach against side-channel attacks, which states that a symmetric encryption scheme is IND-secure in side-channel model, if it is IND-secure in black-box model and there is no adversary who can recover the whole key of the scheme computationally in side-channel model, i.e. WKR-SCA ^ IND -> IND-SCA. Our researches show that it is not the case. We analyze notions of security against key recovery attacks and security against distinguishing attacks, and then construct a scheme which is WKR-SCA-secure and IND-secure, but not IND-SCA-secure in the same side-channel environment. Furthermore, even if the scheme is secure again partial key recovery attacks in side-channel model, this approach still does not hold true.
2006
ASIACRYPT
2006
EPRINT
The MEM mode is a nonce-based enciphering mode of operation proposed by Chakraborty and Sarkar, which was claimed to be secure against symmetric nonce respecting adversaries. We show that this is not correct by using two very simple attcks. One attack need one decryption and one decryption queries, and the other only need one encryption query.
2006
EPRINT
This paper studies the security of the block ciphers ARIA and Camellia against impossible differential cryptanalysis. Our work improves the best impossible differential cryptanalysis of ARIA and Camellia known so far. The designers of ARIA expected no impossible differentials exist for 4-round ARIA. However, we found some nontrivial 4-round impossible differentials, which may lead to a possible attack on 6-round ARIA. Moreover, we found some nontrivial 8-round impossible differentials for Camellia, whereas only 7-round impossible differentials were previously known. By using the 8-round impossible differentials, we presented an attack on 12-round Camellia without $FL/FL^{-1}$ layers.
2006
EPRINT
Yap, Heng and Goi propose an efficient certificateless signature scheme based on the intractability of the computational Diffie-Hellman problem, and prove that the scheme is secure in the random oracle model. This paper shows that their certificateless signature scheme is vulnerable to key replacement attacks, where an adversary who replaces the public key of a signer can forge valid signatures on any messages for that signer without knowing the signer's private key.
2005
EUROCRYPT
2005
EPRINT
Side-channel attacks are easy-to-implement whilst powerful attacks against cryptographic implementations, and their targets range from primitives, protocols, modules, and devices to even systems. These attacks pose a serious threat to the security of cryptographic modules. In consequence, cryptographic implementations have to be evaluated for their resistivity against such attacks and the incorporation of different countermeasures has to be considered. This paper surveys the methods and techniques employed in these attacks, the destructive effects of such attacks, the countermeasures against such attacks and evaluation of their feasibility and applicability. Finally, the necessity and feasibility of adopting this kind of physical security testing and evaluation in the development of FIPS 140-3 standard are explored. This paper is not only a survey paper, but also more a position paper.
2005
EPRINT
Certificateless public-key cryptosystem is a recently proposed attractive paradigm using public key cryptosystem, which avoids the key escrow inherent in identity-based public-key cryptosystems, and does not need certificates to generate trust in public keys. In 2005, Al-Riyami and Paterson proposed a new certificateless public-key encryption scheme and proved its security in the random oracle model. This paper shows that their scheme is vulnerable to adaptive chosen ciphertext attacks, and presents a countermeasure to overcome such a security flaw.
2004
EPRINT
2004
EPRINT
Identity-based (ID-based) public key cryptosystem can be a good alternative for certificate-based public key setting, especially when efficient key management and moderate security are required. A proxy signature scheme permits an entity to delegate its signing rights to another entity. But to date, no ID-based proxy signature schemes with provable security have been proposed. In this paper, we formalize a notion of security for ID-based proxy signature schemes and propose a scheme based on the bilinear pairings. We show that the security of our scheme is tightly related to the computational Diffie-Hellman assumption in the random oracle model.
2004
EPRINT
The distribution of r-patterns is an important aspect of pseudorandomness for periodic sequences over finite field.The aim of this work is to study the distribution of r-patterns in the Kerdock-code binary sequences and the highest level sequences of primitive sequences over $Z_{2^l}$.By combining the local Weil bound with spectral analysis,we derive the upper bound of the deviation to uniform distribution.As a consequence,the recent result on the quantity is improved.
2004
EPRINT
The notion of quantum secure direct communication (QSDC) has been introduced recently in quantum cryptography as a replacement for quantum key distribution, in which two communication entities exchange secure classical messages without establishing any shared keys previously. In this paper, a quantum secure direct communication scheme using quantum Calderbank-Shor-Steane (CCS) error correction codes is proposed. In the scheme, a secure message is first transformed into a binary error vector and then encrypted(decrypted) via quantum coding(decoding) procedures. An adversary Eve, who has controlled the communication channel, can't recover the secrete messages because she doesn't know the deciphering keys. Security of this scheme is based on the assumption that decoding general linear codes is intractable even on quantum computers.
2004
EPRINT
Identity-based (ID-based) public key cryptosystem can be a good alternative for certificate-based public key setting, especially when efficient key management and moderate security are required. In a $(t,n)$ threshold proxy signature scheme, the original signer delegates the power of signing messages to a designated proxy group of $n$ members. Any $t$ or more proxy signers of the group can cooperatively issue a proxy signature on behalf of the original signer, but $t-1$ or less proxy signers cannot. In this paper, we present an ID-based threshold proxy signature scheme using bilinear pairings. We show the scheme satisfies all security requirements in the random oracle model. To the best of authors' knowledge, our scheme is the first ID-based threshold proxy signature scheme.
2004
EPRINT
In this paper, we introduce a new and natural paradigm for fair exchange protocols, called verifiable probabilistic signature scheme. A security model with precise and formal definitions is presented, and an RSA-based efficient and provably secure verifiable probabilistic signature scheme is proposed. Our scheme works well with standard RSA signature schemes, and the proposed optimistic fair exchange protocol is much concise and efficient, and suitable for practical applications.