1,074 research outputs found
A Randomized Kernel-Based Secret Image Sharing Scheme
This paper proposes a ()-threshold secret image sharing scheme that
offers flexibility in terms of meeting contrasting demands such as information
security and storage efficiency with the help of a randomized kernel (binary
matrix) operation. A secret image is split into shares such that any or
more shares () can be used to reconstruct the image. Each share has a
size less than or at most equal to the size of the secret image. Security and
share sizes are solely determined by the kernel of the scheme. The kernel
operation is optimized in terms of the security and computational requirements.
The storage overhead of the kernel can further be made independent of its size
by efficiently storing it as a sparse matrix. Moreover, the scheme is free from
any kind of single point of failure (SPOF).Comment: Accepted in IEEE International Workshop on Information Forensics and
Security (WIFS) 201
PYTHON IMPLEMENTATION OF VISUAL SECRET SHARING SCHEMES
Visual secret sharing schemes (VSS) represent an important concept of visual cryptography. They permit the sharing of a secret image between multiple participants so that only authorized groups can recover the secret. This paper considers the software implementation of some black-and-white secret images VSS in Python programming language. PIL (Python Imaging Library) provides strong image processing capabilities, making the library suitable for this kind of implementation. We present samples of the results obtained from the software computation and draw some conclusions.visual secret sharing, visual cryptography, Python, PIL (Python Imaging Library)
Secure (n, n + 1)-Multi Secret Image Sharing Scheme Using Additive Modulo
AbstractMulti Secret Image Sharing (MSIS) scheme is a protected method to transmit more than one secret images over a communication channel. Conventionally, only single secret image is shared over a channel at a time. But as technology grew up, there arises a need for sharing more than one secret image. An (n, n)-MSIS scheme is used to encrypt n secret images into n meaningless noisy images that are stored over different servers. To recover n secret images all n noise images are required. At earlier time, the main problem with secret sharing schemes was that one can partially figure out secret images by getting access of n – 1 or fewer noisy images. Due to this, there arises a need of secure MSIS scheme so that by using less than n noisy images no information can be retrieved. In this paper, we propose secure (n, n + 1)-MSIS scheme using additive modulo operation for grayscale and colored images. The experimental results show that the proposed scheme is highly secured and altering of noisy images will not reveal any partial information about secret images. The proposed (n, n + 1)-MSIS scheme outperforms the existing MSIS schemes in terms of security
ESSVCS: an enriched secret sharing visual cryptography
Visual Cryptography (VC) is a powerful technique that combines the notions of perfect ciphers and secret sharing in cryptography with that of raster graphics. A binary image can be divided into shares that are able to be stacked together so as to approximately recover the original image. VC is a unique technique in the sense that the encrypted message can be decrypted directly by the Human Visual System (HVS). The distinguishing characteristic of VC is the ability of secret restoration without the use of computation. However because of restrictions of the HVS, pixel expansion and alignment problems, a VC scheme perhaps can only be applied to share a small size of secret image. In this paper, we present an Enriched Secret Sharing Visual Cryptography Scheme (ESSVCS) to let the VC shares carry more secrets, the technique is to use cypher output of private-key systems as the input random numbers of VC scheme, meanwhile the encryption key could be shared, the shared keys could be associated with the VC shares. After this operation, VC scheme and secret sharing scheme are merged with the private-key system. Under this design, we implement a (k; t; n)-VC scheme. Compared to those existing schemes, our scheme could greatly enhance the ability of current VC schemes and could cope with pretty rich secrets
Naturally Rehearsing Passwords
We introduce quantitative usability and security models to guide the design
of password management schemes --- systematic strategies to help users create
and remember multiple passwords. In the same way that security proofs in
cryptography are based on complexity-theoretic assumptions (e.g., hardness of
factoring and discrete logarithm), we quantify usability by introducing
usability assumptions. In particular, password management relies on assumptions
about human memory, e.g., that a user who follows a particular rehearsal
schedule will successfully maintain the corresponding memory. These assumptions
are informed by research in cognitive science and validated through empirical
studies. Given rehearsal requirements and a user's visitation schedule for each
account, we use the total number of extra rehearsals that the user would have
to do to remember all of his passwords as a measure of the usability of the
password scheme. Our usability model leads us to a key observation: password
reuse benefits users not only by reducing the number of passwords that the user
has to memorize, but more importantly by increasing the natural rehearsal rate
for each password. We also present a security model which accounts for the
complexity of password management with multiple accounts and associated
threats, including online, offline, and plaintext password leak attacks.
Observing that current password management schemes are either insecure or
unusable, we present Shared Cues--- a new scheme in which the underlying secret
is strategically shared across accounts to ensure that most rehearsal
requirements are satisfied naturally while simultaneously providing strong
security. The construction uses the Chinese Remainder Theorem to achieve these
competing goals
Digital certificates and threshold cryptography
This dissertation discusses the use of secret sharing cryptographic protocols for distributing and sharing of secret documents, in our case PDF documents.
We discuss the advantages and uses of such a system in the context of collaborative environments.
Description of the cryptographic protocol involved and the necessary Public Key Infrastructure (PKI) shall be presented. We also provide an implementation of this framework as a “proof of concept” and fundament the use of a certificate extension as the basis for threshold cryptography.
Details of the shared secret distribution protocol and shared secret recovery protocol shall be given as well as the associated technical implementation details.
The actual secret sharing algorithm implemented at this stage is based on an existing well known secret sharing scheme that uses polynomial interpolation over a finite field.
Finally we conclude with a practical assessment of our prototype
Unique Information and Secret Key Agreement
The partial information decomposition (PID) is a promising framework for
decomposing a joint random variable into the amount of influence each source
variable Xi has on a target variable Y, relative to the other sources. For two
sources, influence breaks down into the information that both X0 and X1
redundantly share with Y, what X0 uniquely shares with Y, what X1 uniquely
shares with Y, and finally what X0 and X1 synergistically share with Y.
Unfortunately, considerable disagreement has arisen as to how these four
components should be quantified. Drawing from cryptography, we consider the
secret key agreement rate as an operational method of quantifying unique
informations. Secret key agreement rate comes in several forms, depending upon
which parties are permitted to communicate. We demonstrate that three of these
four forms are inconsistent with the PID. The remaining form implies certain
interpretations as to the PID's meaning---interpretations not present in PID's
definition but that, we argue, need to be explicit. These reveal an
inconsistency between third-order connected information, two-way secret key
agreement rate, and synergy. Similar difficulties arise with a popular PID
measure in light the results here as well as from a maximum entropy viewpoint.
We close by reviewing the challenges facing the PID.Comment: 9 pages, 3 figures, 4 tables;
http://csc.ucdavis.edu/~cmg/compmech/pubs/pid_skar.htm. arXiv admin note:
text overlap with arXiv:1808.0860
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