Dynamic Searchable Symmetric Encryption for Multiuser (M-DSSE) is an advanced form of symmetric encryption. It extends the traditional symmetric encryption to support the operations of adding and deleting the encrypted data and allow an authenticated group of data users to retrieve their respective desired encrypted data in the dynamic database. However, M-DSSE would suffer from the privacy concerns regarding forward and backward security. The former allows an attacker to identify the keywords contained in the added data by lunching file-injection attacks, while the latter allows to utilize the search results and the deleted data to learn the content. To our knowledge, these privacy concerns for M-DSSE have not been fully considered in the existing literatures. Taking account of this fact, we focus on the dynamic searchable symmetric encryption for multiuser meeting the needs of forward and backward security. In order to propose a concrete scheme, the primitives of Pseudorandom Functions (PRF) and the Homomorphic Message Authenticator (HMAC) are employed to construct the inverted index and update the search token. The proposed scheme is proven secure in the random model. And the performance analysis shows that the proposed scheme achieves the enhanced security guarantees at the reasonable price of efficiency.

中文翻译：

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具有前向和后向安全性的多用户动态可搜索对称加密方案

多用户动态可搜索对称加密（M-DSSE）是对称加密的高级形式。它扩展了传统的对称加密，以支持添加和删除加密数据的操作，并允许一组经过身份验证的数据用户在动态数据库中检索其各自所需的加密数据。但是，M-DSSE将遭受有关前向和后向安全性的隐私问题。前者允许攻击者通过对文件注入攻击进行午餐来识别添加的数据中包含的关键字，而后者则允许利用搜索结果和已删除的数据来学习内容。据我们所知，在现有文献中尚未充分考虑到M-DSSE的这些隐私问题。考虑到这一事实，我们专注于满足前向和后向安全需求的多用户动态可搜索对称加密。为了提出一个具体的方案，采用伪随机函数（PRF）和同态消息认证器（HMAC）的原语来构造倒排索引并更新搜索令牌。所提出的方案在随机模型中被证明是安全的。性能分析表明，该方案以合理的效率价格获得了增强的安全保证。