In this work, we show that zero storage overhead is achievable for tree-shaped databases. In particular, we develop TreePIR, a novel approach tailored made for private retrieval of the set of nodes along an arbitrary root-to-leaf path in a Merkle tree with no storage redundancy.

2022年5月11日 · In this work, we show that \textit {zero} storage overhead is achievable for tree-shaped databases. In particular, we develop TreePIR, a novel approach tailored made for private retrieval of the set of nodes along an arbitrary root-to-leaf …

2023年2月15日 · In this paper we propose TreePIR, a two-server PIR protocol with sublinear amortized server time and polylogarithmic bandwidth whose security can be based on just the DDH assumption. TreePIR can be partitioned in two phases, both sublinear: The first phase is remarkably simple and only requires pseudorandom generators.

We use our sets to construct TreePIR by creating a new file pir/pir_punc_tree.go with our pir implementation, and significantly modifying pir/pset.go. Other than this there were small modifications and optimizations across many files with respect to the original repo.

GGM伪随机函数 （PRF）利用长度加倍的PRG去将一颗随机种子转换成一整个很长的伪随机串，在每一层的每一个节点，可以选择向左子树走或者向右子树走，以此扩展成一棵树。 我们要在生成算法中构建给到两方的密钥。 最开始给定两个不同的随机PRG种子，根据这两个种子会构建出两棵不同的伪随机函数的树。 但这目前还不能满足我们要构建一个紧凑的点函数的目标。 我们的目标是去秘密分享在所有其他地方都几乎相等，只要在特定点函数alpha路径上才不同的函数。 …

In Private Information Retrieval (PIR), a server holds a public database DB represented as a string of N bits, and a client holds an index i. The goal of the protocol is for the client to learn DB[i] without the server learning i.

TreePIR: Efficient Private Retrieval of Merkle Proofs via Tree Colorings with Fast Indexing and Zero Storage Overhead - PIR-PIXR/TreePIR

2023年2月13日 · In this talk, I introduce TreePIR, a two-server PIR protocol with sublinear amortized server time and polylogarithmic bandwidth whose security can be based on just the DDH assumption. TreePIR can...

2023年8月30日 · PIR 全称为 Private Information Retrival，直观的翻译名字为“私有信息检索”。 已知的最早提出 PIR 的文章是 1995 年 Benny Chor, et. al. [1]。 在文章最开始的时候，提到了在传统的 query 场景中，我们有一个 client 发送 query，有 server 回复结果。 从抽象角度来看，我们可以试图保护： 在 [1] 之前，有许多工作在研究如何保护 server 端 DB 数据的安全性，在此不再赘述。 Benny Chor, et. al. [1] 提出了一个问题：我们是否可以在 query 场景中保护 client query 的隐私 …

In particular, we develop TreePIR, a novel approach tailored made for private retrieval of the set of nodes along an arbitrary root-to-leaf path in a Merkle tree with no storage redundancy. This type of trees has been widely implemented in many real-world systems such as Amazon DynamoDB, Google’s Certificate Transparency, and blockchains.