We present the first Identity-Based Encryption (IBE) schemes that are proven secure against selective opening attack (SOA). This means that if an adversary, given a vector of ciphertexts, adaptively corrupts some fraction of the senders, exposing not only their messages but also their coins, the privacy of the unopened messages is guaranteed. Achieving security against such attacks is well-know...

Identity based encryption (IBE) has received great attention since Boneh and Franklin’s breakthrough work on bilinear group based IBE [4]. Till now, many IBE schemes relying on bilinear groups with different properties have been proposed [5, 25, 29, 14]. However, one part of the user’s private key in all these IBE schemes is constructed as y = f(msk), where msk is the master key and y is an ele...

Security against selective opening attack (SOA) requires that in a multi-user setting, even if an adversary has access to all ciphertexts from users, and adaptively corrupts some fraction of the users by exposing not only their messages but also the random coins, the remaining unopened messages retain their privacy. Recently, Bellare, Waters and Yilek considered SOA-security in the identity-bas...

In this paper we analyze and find an anomaly in the security proof of the identity-based encryption (IBE) scheme fullM-IBE of Wang and Cao [9], which is based on mBDHP. Here we give another proof for fullM-IBE which is based on Bilinear Diffie-Hellman Problem (BDHP). We also obtain a tightness improvement using a stronger assumption, namely, the Bilinear Inverse Dicision Diffie-Hellman problem ...

Ecologists urgently need a better ability to predict how environmental change affects biodiversity. We examine individual-based ecology (IBE), a research paradigm that promises better a predictive ability by using individual-based models (IBMs) to represent ecological dynamics as arising from how individuals interact with their environment and with each other. A key advantage of IBMs is that th...

Identity-based encryption (IBE) allows one party to send ciphered messages to another using an arbitrary identity string as an encryption key. Since IBE does not require prior generation and distribution of keys, it greatly simplifies key management in public-key cryptography. Although the concept of IBE was introduced by Shamir in 1981, constructing a practical IBE scheme remained an open prob...

We construct two efficient Identity Based Encryption (IBE) systems that are selective identity secure without the random oracle model in groups equipped with a bilinear map. Selective identity secure IBE is a slightly weaker security model than the standard security model for IBE. In this model the adversary must commit ahead of time to the identity that it intends to attack, whereas in the sta...

PURPOSE To determine the 12-year risk of developing an ipsilateral breast event (IBE) for women with ductal carcinoma in situ (DCIS) of the breast treated with surgical excision (lumpectomy) without radiation. PATIENTS AND METHODS A prospective clinical trial was performed for women with DCIS who were selected for low-risk clinical and pathologic characteristics. Patients were enrolled onto o...

By a generic transformation by Canetti, Halevi, and Katz (CHK) every Identity-based encryption (IBE) scheme implies a chosen-ciphertext secure public-key encryption (PKE) scheme. In the same work it is claimed that this transformation maps the two existing IBE schemes to two new and different chosenciphertext secure encryption schemes, each with individual advantages over the other. In this wor...