Improvements on Security Proofs of Some Identity Based Encryption Schemes
Improvements on Security Proofs of Some Identity Based Encryption Schemes
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DOI：
10.1007/11599548_3
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发表时间：
2005-11
期刊：
影响因子：
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通讯作者：
Rui Zhang;H. Imai
中科院分区：
文献类型：
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作者：
Rui Zhang;H. Imai
具体的安全降低在实践中扮演着重要的角色，因为它明确地将对手的成功概率限定为他们的资源的函数。本文研究了Boneh-Franklin基于身份加密(IBE)方案及其变种的安全性降阶，重点讨论了它们的安全性降阶的效率：对Boneh-Franklin Ibe及其变种的证明进行了改进。直到最近，Boneh-Franklin Ibe(BF-IBE)方案的证明一直被认为是正确的，Galindo指出了证明中的一个缺陷，并给出了一个新的证明，然而，新的证明更加松散。我们给出了BF-IBE方案的一个新证明，本质上改进了已有的结果。非常有趣的是，我们的结果甚至比最初被低估的结果还要好。类似的分析也可以应用于Galindo的BF-IBE变形，从而得到更紧的约简。我们提出了BF-IBE的另一种变形，它允许更好的安全性约简，但该方案依赖于更强的假设，即Gap双线性Diffie-Hellman(GBDH)假设。
Concrete security reduction plays an important role in practice, because it explicitly bounds an adversary’s success probability as a function of their resources. In this paper, we study the security reductions of Boneh-Franklin identity based encryption (IBE) schemes and its variants, focusing on the efficiency of their security reductions:Improvements on proofs of Boneh-Franklin IBE and variants.The proof of the Boneh-Franklin IBE (BF-IBE) scheme was long believed to be correct until recently, Galindo pointed out a flawed step in the proof and gave a new proof, however, the new reduction was even looser. We give a new proof of the BF-IBE scheme that essentially improves previously known results. Very interestingly, our result is even better than the original underestimated one. Similar analysis can also be applied to Galindo’s BF-IBE variant, resulting in a tighter reduction.A new BF-IBE variant with tighter security reductions.We propose another variant of the BF-IBE that admits better security reduction, however, the scheme relies on a stronger assumption, namely the Gap Bilinear Diffie-Hellman (GBDH) assumption.