Proxy ring (anonymous proxy) signatures allow an entity to delegate its signing capability to a group of entities (proxy group) such that only one of the members in the proxy group can generate a proxy signature on behalf of the delegator while privacy of the proxy signer is protected. Identity-based versions of proxy ring signatures employ identity strings in place of randomly generated public...

A proxy re-encryption scheme (PRE) allows a semi-trusted proxy to convert a ciphertext encrypted under one key into a ciphertext encrypted under another key without leaking the underlying plaintext. In the process of the arithmetic processing, proxy should be able to learn as little information about the plaintext as possible. Conditional proxy re-encryption (CPRE) is a new cryptography primiti...

Proxy cryptosystem, first proposed by Mambo and Okamoto [M.Mambo, E. Okamoto, Proxy cryptosystem: delegation of a power to decrypt ciphertexts, IEICE Trans. Fundam. Electron. Commun. Comput. Sci. E80-A/1 (1997) 54–63], allows the original decryptor to delegate his decrypting capability to the proxies. However, until now, no practical proxy cryptosystem modes are proposed. Therefore, in this pap...

In a proxy signature scheme, one original signer delegates a proxy signer to sign messages on behalf of the original signer. When the proxy signature is created, the proxy signer generates valid proxy signatures on behalf of the original signer. Based on Cha and Cheon’s ID-based signature scheme, a model of designated-verifier proxy signature scheme from the bilinear pairing is proposed. The pr...

We have designed and validated a rapid, accurate simulation method for evaluating the performance of Web proxy cache replacement algorithm designs. We model the client-proxy-server system by combining a linear model of client-proxy response times with real measurements of proxy-server response times. We experimentally validate the model’s accuracy on the Apache proxy server. Our method should b...

A proxy signature scheme allows one user to delegate his/her signing authority to another user called a proxy signer in such a way that the latter can sign messages on behalf of the former. Moreover, after verification, the verifier is convinced of the original signer’s agreement on the signed message. There exist several certificateless proxy signature schemes in the literature, but all of the...

A proxy signature scheme allows an entity to delegate its signing capability to another entity (proxy) in such a way that the proxy can sign messages on behalf of the delegator. Proxy signatures have found numerous practical applications such as distributed systems, mobile agent applications, etc. Recently, Xu, Zhang and Feng proposed the first formal models of identity based proxy signature. U...

This paper studies measuring the average e¤ects  of X on Y in a structural system with random coe¢ cients and confounding. We do not require (conditionally) exogenous regressors or instruments. Using proxies W for the confounders U , we ask how do the average direct e¤ects of U on Y compare in magnitude and sign to those of U on W . Exogeneity and equior proportional confounding are limit case...

This paper estimates the implied cost of equity for Canadian and U.S. firms using a methodology based on the dividend discount model and utilizing firms’ current stock price and analysts’ forecasted earnings. We find that firm size and firm stock liquidity are negatively related to cost of equity, while greater firm financial leverage and greater dispersion in analysts’ earnings forecasts are a...