PMTER-ABE: a practical multi-authority CP-ABE with traceability, revocation and outsourcing decryption for secure access control in cloud systems

A Review on Challenges in Cloud Computing Security and Recent Researchs

“…Bulut servis sağlayıcılarının güvenilmez olduğu varsayımıyla hareket edilen çalışmada [15], çoklu özellik otoritesi ve tek sertifika otoritesinin olduğu çok otoriteli özellik tabanlı şifrelemeli bir erişim kontrol sistemi ortaya koyulmuştur. Özellik tabanlı şifreleme şeması kullanılan diğer bir çalışmada [16], detaylı politikalarla özellik uzayını birleştirilmes i, kullanıcı kontrolü altında ileri ve geri gizliliğ in entegrasyonu ve kötücül kullanıcıların takip edilmes i sağlanmış, ayrıca şifre çözme işlemlerinin dış kaynaklarca yapılabilmesine imkân tanınmıştır. Özellik tabanlı şifreleme kullanan, dinamik erişim kontrolü yapabilen ve izlenebilir bir sistemin (TABE-DAC) sunulduğu çalışmada [17], gizli anahtarlarını sızdıran kötücül kullanıcıların izlenebilmesi ve erişim yetkilerinin veri sahipleri tarafından dinamik bir şekilde yönetilmesi amaçlanmışt ır.…”

You Are Revoked and Out: Towards Directly Revocable Ciphertext-Policy Attribute-Based Encryption

“…As shown in Table 1, the schemes of Ning et al [6], Liu et al [15], Sethi et al [27], Han et al [22], and this proposal all provide traceability, but Ning et al's scheme [6] does not sustain a revocation mechanism, and it cannot revoke a malicious user to ensure security even if that malicious user is traced. Meanwhile, [27] adopts an indirect revocation mechanism and cannot revoke a malicious user timely. Since a malicious user is desired to be revoked immediately, a direct revocation mechanism is more suitable for a CP-ABE with traceability.…”

“…Since a malicious user is desired to be revoked immediately, a direct revocation mechanism is more suitable for a CP-ABE with traceability. e schemes of Liu et al [15], Xu et al [28], Sethi et al [27], Han et al [22], and this proposal try to support the ciphertext update when revocation occurs. e difference is that neither [15] nor [22] can resist user collusion attacks among users, and they cannot provide sufficient forward and backward secrecy.…”

“…Sahai et al [8] firstly discussed this situation and dealt with it by introducing a ciphertext delegation that allows a ciphertext to be updated using only public information. In the follow-up schemes, ciphertext update falls into two types: partial update [24,25] and full update [26][27][28][29]. In the partial update, only those components associated with the revocation mechanism are updated.…”

“…e latter provides better protection as any intermediate values computed for the previous ciphertext will be useless for decrypting the refreshed ciphertext. Among recent published schemes that support ciphertext update functionality [24][25][26][27][28][29], only Li et al [25] and Sethi et al [27] realized traceability, but the access policy of [25] can only be expressed as AND gate that sacrifices the flexibility and expressiveness of the CP-ABE. Sethi et al [27] adopted the expressive linear secret-sharing schemes (LSSS) into access policy, but their proposal is an indirect revocable scheme that allows malicious users to maintain decryption capabilities until the next key update.…”