In this paper we present a system towards the recognition of off-line Oriya handwritten characters. Since most of the Oriya characters have curve-like stroke, we use curvature feature for the recognition purpose. To get the feature, at first, the input image is size normalized and segmented into 49times49 blocks. Curvature is then computed using bi-quadratic interpolation method and quantized into 3 levels according to concave, linear and convex regions. Next direction of gradient is quantized into 32 levels with pi/16 intervals, and strength of the gradient is accumulated in each of the 32 directions and in each of the 3 curvature levels of every block. A spatial resolution is made to get 7times7 blocks from 49times49 blocks and a directional resolution is made to get 8 directions from 32 directions. Using curvature features for 3 levels we get 1176 (7times7 blocks times 8 directions times 3 levels) dimensional features. Finally using principal component analysis we reduce the dimension 1176 to 392 and this 392 dimensional feature vector is fed to a quadratic classifier for recognition. We tested 18190 samples of Oriya handwritten samples and obtained 94.60% accuracy from our proposed system.

A System for Off-Line Oriya Handwritten Character Recognition Using Curvature Feature

In 2000, Shieh et al. proposed some multisignature schemes based on a new digital signature scheme to satisfy the special requirements of the mobile system. In these schemes, one-way hash functions and message redundancy schemes are not used. Later, Hwang and Li indicated that Shieh et al.'s digital signature scheme suffers from the forgery attacks. They also claimed that message redundancy schemes should still be used to resist some attacks. In this letter, we show another attack on Shieh et al.'s signature scheme and propose a secure digital signature scheme, where neither one-way hash functions nor message redundancy schemes are employed.

Signing a digital signature without using one-way hash functions and message redundancy schemes

In this article, a secure and verifiable electronic voting scheme is proposed. Encrypted votes are accumulated and prepared in the form of block on each electronic polling booth at the end of polling time. The resultant block from each electronic polling booth is distributed to the authorized nodes of group for temper proof block chaining that assures the internal verifiability. The external verifiability is attained through the redistribution of temper proof Blockchain ledger to the validated and authorized nodes of auditing group. The temper proof property of electoral data is achieved using an emerging Blockchain Technology. Whereas the secure data distribution in the form of temper proof blocks and ledger amongst the authenticated group members is accomplished through the cryptographically secure group oriented scenario. The individual and universal verifiability features in our proposed scheme make the electoral process transparent, reliable and verifiable.

Temper proof data distribution for universal verifiability and accuracy in electoral process using blockchain

Summary In this paper, a novel Blind Signature Scheme (BSS) has been proposed. The scheme is based on Elliptic Curve Discrete Logarithm Problem (ECDLP). It allows a requester to obtain signature from a signer on any document, in such a way that the signer learns nothing about the message that is being signed. The scheme utilizes the inherent advantage of Elliptic Curve Cryptosystem in terms of smaller key size and lower computational overhead to its counterpart public cryptosystems such as RSA and ElGamal. The scheme has been proved to be robust, untraceable and correct. The proposed scheme can be used in various applications like E-voting, digital cash etc where anonymity of requester is required.

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A Novel Untraceable Blind Signature Based on Elliptic Curve Discrete Logarithm Problem

Due to the special requirements of the mobile code system, Shieh et al. (see IEEE Trans. Veh. Technol., vol.49, p.1464-73, July 2000) proposed some multisignature schemes based on a new digital signature scheme with message recovery. One major characteristic of these schemes is to avoid using one-way hash functions and message redundancy schemes. However, this causes some security flaw. An attack is proposed to show that the underlying signature scheme is not secure. To overcome the attack, the message redundancy schemes may be still used.

Cryptanalysis of Shieh-Lin-Yang-Sun signature scheme

Fan et al. [1998] proposed a fast blind signature scheme with extremely low computations for requesters. The author points out that this scheme is not a true blind signature and proposes an improved user efficient blind signature scheme. The blind property of the improved blind signature scheme is discussed.

Improved user efficient blind signatures

A new digital signature scheme which does not use a one-way hash function is proposed, the security of which is based on the difficulties of computing discrete logarithms, and the performance of which is similar to those of DSS and RSA. The new scheme can resist both homomorphism and substitution attacks.

Zuhua Shao

Papers

Improved user efficient blind signatures

Signature scheme based on discrete logarithm without using one-way hash function