A Novel Revocable and Identity-Based Conditional Proxy Re-Encryption Scheme With Ciphertext Evolution for Secure Cloud Data Sharing

Abstract

Proxy re-encryption (PRE), with the unique ciphertext transformation ability, enables various ciphertext authorization applications to be implemented efficiently. However, most existing PRE schemes mainly focus on access authorization while ignoring the situation where the key needs to be changed and the ciphertext needs to be evolved, making the scheme's practicability and security inadequate. Moreover, the few schemes that simultaneously combine ciphertext authorization, key update, and ciphertext evolution are not satisfactory in terms of security. For solving this problem, based on Xiong et al.'s scheme, this paper proposes an improved revocable and identity-based conditional proxy re-encryption scheme with ciphertext evolution (RIB-CPRE-CE) for secure and efficient cloud data sharing. The proposed scheme inherits the characteristics of multi-use, constant ciphertext length, fine-grained authorization, collisionresistance security, and chosen ciphertext attack (CCA) security from the original method. Also, it supports updating ciphertext to adapt to the new key after changing the identity (key) or achieves authorization revocation by evolving ciphertext. Two new algorithms, URKeyGen and UpReEnc, have been integrated into the original delegation scheme to support ciphertext evolution. The formal definition, security model, concrete construction, and security analysis of RIB-CPRE-CE have been presented. The comparison and analysis show that the proposed scheme is practical and secure. Although it adds a ciphertext evolution function for supporting key update and delegation revocation, its efficiency and security are not reduced. The proposed scheme can also be used in other access authorization systems that need to change the key or revoke the authorization. It has certain practicability and security.

Pairing-Free Certificate-Based Proxy Re-Encryption Plus Scheme for Secure Cloud Data Sharing

“…Proxy Re-Encryption (PRE) has received increased academic attention recently, leading to the development of several well-known PRE schemes [2][3][4][5][6]. However, many of these schemes rely on traditional public-key cryptosystems (PKC) [7][8][9][10] or identity-based cryptosystems [11][12][13][14], which can introduce certain limitations and challenges.…”

“…(b) The algorithm calculates user i's certificate Cert i = y i + αH 1 (id i , pk i ). 4. Encrypt: On inputting message m ∈ {0, 1} n , identity id A , the public key pk A = (pk A1 , pk A2 ), and public parameter params, the user does the following:…”

Advanced set containment deep learned Rabin certificateless signcryption for secured transmission with big data in cloud

“…But, the designed method was not efficient to attain higher data confidentiality. An improved revocable and identity‐based conditional proxy re‐encryption (RIB‐CPRE) method was introduced in reference 13 with ciphertext evolution (CE) for secure and efficient cloud data sharing. But, the computational complexity of the algorithms was improved.…”

A Review on Challenges in Cloud Computing Security and Recent Researchs

“…Bu maksatla, şifreleme algoritmaları başta olmak üzere çeşitli teknikler kullanılarak çalışmalar gerçekleştirilmekted ir. Çalışmada [20], bulut ortamında güvenli ve etkin beri paylaşımı kapsamında, mevcut vekil yeniden şifreleme şemalarındaki uygulanabilirlik ve güvenlik ile ilgili yetersizlikleri gidermek için, kimlik tabanlı durumsal vekil yeniden şifreleme şeması (RIB-CPRE-CE) sunulmuştur. Bulut ortamında güvenli veri paylaşımı için blok zincir tabanlı şifreli metin politikalı özellik tabanlı şifreleme şemasının (BCAS) ortaya konulduğu çalışmada [21], veri sahiplerinin veriyi çözebilecek kullanıcıları belirlemesin e imkân sağlayan, kullanıcı işlemlerini süresiz saklayan bireçok şifreleme yaklaşımıyla verinin bir kez şifrelenmesinin yeterli olduğu bir sistem sunulmuştur.…”