8,017 research outputs found
Cryptanalysis of an Encryption Scheme Based on Blind Source Separation
Recently Lin et al. proposed a method of using the underdetermined BSS (blind
source separation) problem to realize image and speech encryption. In this
paper, we give a cryptanalysis of this BSS-based encryption and point out that
it is not secure against known/chosen-plaintext attack and chosen-ciphertext
attack. In addition, there exist some other security defects: low sensitivity
to part of the key and the plaintext, a ciphertext-only differential attack,
divide-and-conquer (DAC) attack on part of the key. We also discuss the role of
BSS in Lin et al.'s efforts towards cryptographically secure ciphers.Comment: 8 pages, 10 figures, IEEE forma
On the security of the Yen-Guo's domino signal encryption algorithm (DSEA)
Recently, a new domino signal encryption algorithm (DSEA) was proposed for
digital signal transmission, especially for digital images and videos. This
paper analyzes the security of DSEA, and points out the following weaknesses:
1) its security against the brute-force attack was overestimated; 2) it is not
sufficiently secure against ciphertext-only attacks, and only one ciphertext is
enough to get some information about the plaintext and to break the value of a
sub-key; 3) it is insecure against known/chosen-plaintext attacks, in the sense
that the secret key can be recovered from a number of continuous bytes of only
one known/chosen plaintext and the corresponding ciphertext. Experimental
results are given to show the performance of the proposed attacks, and some
countermeasures are discussed to improve DSEA.Comment: 11 pages, 5 figure
On the Security of the Yi-Tan-Siew Chaos-Based Cipher
This paper presents a comprehensive analysis on the security of the
Yi-Tan-Siew chaotic cipher proposed in [IEEE TCAS-I 49(12):1826-1829 (2002)]. A
differential chosen-plaintext attack and a differential chosen-ciphertext
attack are suggested to break the sub-key K, under the assumption that the time
stamp can be altered by the attacker, which is reasonable in such attacks.
Also, some security Problems about the sub-keys and are
clarified, from both theoretical and experimental points of view. Further
analysis shows that the security of this cipher is independent of the use of
the chaotic tent map, once the sub-key is removed via the proposed
suggested differential chosen-plaintext attack.Comment: 5 pages, 3 figures, IEEEtrans.cls v 1.
Security of a biometric identity-based encryption scheme
Biometric identity-based encryption (Bio-IBE) is a kind of fuzzy
identity-based encryption (fuzzy IBE) where a ciphertext encrypted under an
identity w' can be decrypted using a secret key corresponding to the identity w
which is close to w' as measured by some metric. Recently, Yang et al. proposed
a constant-size Bio-IBE scheme and proved that it is secure against adaptive
chosen-ciphertext attack (CCA2) in the random oracle model. Unfortunately, in
this paper, we will show that their Bio-IBE scheme is even not chosen-plaintext
secure. Specifically, user w using his secret key is able to decrypt any
ciphertext encrypted under an identity w' even though w is not close to w'.Comment: Journal version of the paper will be appearing in International
Journal of Network Securit
Unforgeable Quantum Encryption
We study the problem of encrypting and authenticating quantum data in the
presence of adversaries making adaptive chosen plaintext and chosen ciphertext
queries. Classically, security games use string copying and comparison to
detect adversarial cheating in such scenarios. Quantumly, this approach would
violate no-cloning. We develop new techniques to overcome this problem: we use
entanglement to detect cheating, and rely on recent results for characterizing
quantum encryption schemes. We give definitions for (i.) ciphertext
unforgeability , (ii.) indistinguishability under adaptive chosen-ciphertext
attack, and (iii.) authenticated encryption. The restriction of each definition
to the classical setting is at least as strong as the corresponding classical
notion: (i) implies INT-CTXT, (ii) implies IND-CCA2, and (iii) implies AE. All
of our new notions also imply QIND-CPA privacy. Combining one-time
authentication and classical pseudorandomness, we construct schemes for each of
these new quantum security notions, and provide several separation examples.
Along the way, we also give a new definition of one-time quantum authentication
which, unlike all previous approaches, authenticates ciphertexts rather than
plaintexts.Comment: 22+2 pages, 1 figure. v3: error in the definition of QIND-CCA2 fixed,
some proofs related to QIND-CCA2 clarifie
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