# \#studygroup **URL:** https://forum.openzeppelin.com/tag/studygroup/24.md [Latest](https://forum.openzeppelin.com/latest.md) · [Categories](https://forum.openzeppelin.com/categories.md) · [Tags](https://forum.openzeppelin.com/tags.md) --- ## [Proof of Authority](https://forum.openzeppelin.com/t/proof-of-authority/3577)
**Author:** [@SmritiVerma](https://forum.openzeppelin.com/u/SmritiVerma)\ **Replies:** 3\ **Last updated:** [August 25, 2020, 2:44am UTC](https://forum.openzeppelin.com/t/proof-of-authority/3577 "2020-08-25T02:44:04Z")
This post is part of our Blockchains Study Group and the Cryptography series . Take a look there to learn more about related topics. Prerequisite knowledge: Proof of Stake The Proof of Authority (PoA) consensus a… --- ## [The Byzantine Generals Problem](https://forum.openzeppelin.com/t/the-byzantine-generals-problem/1652)
**Author:** [@elopio](https://forum.openzeppelin.com/u/elopio)\ **Replies:** 0\ **Last updated:** [October 30, 2019, 2:08am UTC](https://forum.openzeppelin.com/t/the-byzantine-generals-problem/1652 "2019-10-30T02:08:27Z")
This post is part of our Blockchains Study Group. Take a look there to learn more about related topics. The Byzantine Generals Problem is a white paper written by Leslie Lamport, Robert Shostak, and Marshall Pease … --- ## [Proof of work](https://forum.openzeppelin.com/t/proof-of-work/1759)
**Author:** [@elopio](https://forum.openzeppelin.com/u/elopio)\ **Replies:** 0\ **Last updated:** [November 29, 2019, 12:04am UTC](https://forum.openzeppelin.com/t/proof-of-work/1759 "2019-11-29T00:04:08Z")
This post is part of our Blockchains Study Group and the Cryptography series. Take a look there to learn more about related topics. Prerequisite knowledge: Hash functions. I found this video from the Binance Acade… --- ## [Proof of stake](https://forum.openzeppelin.com/t/proof-of-stake/3106)
**Author:** [@SmritiVerma](https://forum.openzeppelin.com/u/SmritiVerma)\ **Replies:** 3\ **Last updated:** [June 23, 2020, 3:11am UTC](https://forum.openzeppelin.com/t/proof-of-stake/3106 "2020-06-23T03:11:31Z")
This post is part of our Blockchains Study Group and the Cryptography series . Take a look there to learn more about related topics. Prerequisite knowledge: Proof of Work With Eth2.0 just around the corner, it is… --- ## [Classification of Blockchains](https://forum.openzeppelin.com/t/classification-of-blockchains/1648)
**Author:** [@elopio](https://forum.openzeppelin.com/u/elopio)\ **Replies:** 6\ **Last updated:** [January 30, 2020, 7:02pm UTC](https://forum.openzeppelin.com/t/classification-of-blockchains/1648 "2020-01-30T19:02:59Z")
This post is part of our Blockchains Study Group. Take a look there to learn more about related topics. In the Telegram white paper, they present a very useful classification of blockchains. I think it is a little … --- ## [Polkadot \[in progress\]](https://forum.openzeppelin.com/t/polkadot-in-progress/1818)
**Author:** [@elopio](https://forum.openzeppelin.com/u/elopio)\ **Replies:** 3\ **Last updated:** [November 26, 2019, 12:46am UTC](https://forum.openzeppelin.com/t/polkadot-in-progress/1818 "2019-11-26T00:46:43Z")
This post is part of our Blockchains Study Group. Take a look there to learn more about related topics. Polkadot is a heterogeneous multi-chain system with Nominated Proof of Stake (NPoS). It has one relay chain a… --- ## [Blockchains Study Group](https://forum.openzeppelin.com/t/blockchains-study-group/1647)
**Author:** [@elopio](https://forum.openzeppelin.com/u/elopio)\ **Replies:** 2\ **Last updated:** [November 4, 2019, 11:03pm UTC](https://forum.openzeppelin.com/t/blockchains-study-group/1647 "2019-11-04T23:03:10Z")
Overview At OpenZeppelin we have learned many topics related to blockchains, and we continue to learn more with every audit we perform. We now want to organize and publish these learnings, and to invite our community t…