# Implementing History Aware IPNS Via Certificate Transparency Log Data Structure Trillian

**URL:** <https://discuss.ipfs.tech/t/implementing-history-aware-ipns-via-certificate-transparency-log-data-structure-trillian/5756>\
**Category:** Ecosystem and Usage\
**Tags:** ipns\
**Created:** [June 28, 2019, 3:19pm UTC](https://discuss.ipfs.tech/t/implementing-history-aware-ipns-via-certificate-transparency-log-data-structure-trillian/5756 "2019-06-28T15:19:41Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![ibnesayeed](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ipfs.tech/ibnesayeed/32/2379_2.png) [@ibnesayeed](https://discuss.ipfs.tech/u/ibnesayeed)\
**Post date:** [June 28, 2019, 3:19pm UTC](https://discuss.ipfs.tech/t/implementing-history-aware-ipns-via-certificate-transparency-log-data-structure-trillian/5756/1 "2019-06-28T15:19:41Z")

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I previously proposed [IPNS Blockchain](https://discuss.ipfs.tech/t/ipns-blockchain/2321) as a means to make IPNS history-aware. Current IPNS implementation only returns the most recent mapping of a URI to its content-hash. Adding [Memento](https://www.mementoweb.org/about/) support to IPNS would enable IPFS to facilitate a self-archiving web.

> **[oduwsdl/IPNS-Blockchain](https://github.com/oduwsdl/IPNS-Blockchain)**
>
> An IPNS implementation using Blockchain with Memento support - oduwsdl/IPNS-Blockchain

Last year, I gave a talk entitled, “[InterPlanetary Wayback: The Next Step Towards Decentralized Archiving](https://www.slideshare.net/ibnesayeed/interplanetary-wayback-the-next-step-towards-decentralized-web-archiving-108525567)”, at the [IPFS Lab Day](https://lab-day.com/) after the [DWeb Summit 2018](https://www.decentralizedweb.net/). In that talk I outlined current limitations of web archiving and potential solutions that a decentralized web can bring to the table. However, IPNS not being history-aware was a blocking issue.

https://www.slideshare.net/slideshow/embed_code/key/ugAjuU8LkwpZfx

> **[oduwsdl/ipwb](https://github.com/oduwsdl/ipwb)**
>
> InterPlanetary Wayback: A distributed and persistent archive replay system using IPFS - oduwsdl/ipwb

Recently, I was looking at the [Trillian](https://github.com/google/trillian), a verifiable, tamper-proof, append-only, and Merkle tree-based data structure proposed by Google for [Certificate Transparency (CT)](https://certificate-transparency.org/), which is being used by many Certificate Authorities (including [Let’s Encrypt](https://letsencrypt.org/2019/05/15/introducing-oak-ct-log.html)). I think we can use it as a supplementary system to push selected IPNS records into it that we want to be history-aware. Then we can implement Memento endpoints on top of it.

> **[google/trillian](https://github.com/google/trillian)**
>
> A transparent, highly scalable and cryptographically verifiable data store. - google/trillian