Secret sharing, a well-known cryptographic technique, introduced 40 years ago as a private and reliable variant of classical storage, has now become a major cryptographic primitive with numerous real-world applications. In this paper we consider the digital forensics aspects of secret sharing. We investigate the problem of framing which occurs when a coalition is able to calculate the share of a participant who does not belong to it. In the extreme case one authorized coalition can calculate shares of another authorized coalition and use the secret in some way blaming another authorized coalition for their action. In this context seniority plays an important role. We define seniority, which comes natural in the context of hierarchical access structures. Roughly speaking, our work shows that in an ideal secret sharing scheme an authorized coalition cannot frame participants who are less senior than all members of the coalition and is able to frame a participant who is more senior than at least one pivotal member of the coalition. We show that for any monotone access structure there exists a (non-ideal) frameproof secret sharing scheme.

中文翻译：

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秘密分享中的框架


秘密共享是一种众所周知的密码技术，40 年前作为经典存储的私有且可靠的变体引入，现已成为具有众多实际应用的主要密码原语。在本文中，我们考虑秘密共享的数字取证方面。我们研究了当联盟能够计算不属于该联盟的参与者的份额时出现的框架问题。在极端情况下，一个授权联盟可以计算另一个授权联盟的份额，并以某种方式使用该秘密来指责另一个授权联盟的行为。在这种情况下，资历起着重要作用。我们定义了资历，这在分层访问结构的背景下是自然而然的。粗略地说，我们的工作表明，在理想的秘密共享方案中，授权联盟不能陷害比联盟所有成员级别低的参与者，并且能够陷害比联盟中至少一名关键成员级别更高的参与者。我们证明，对于任何单调访问结构，都存在一个（非理想的）防帧秘密共享方案。