Obelisk is a blockchain consensus algorithm developed by Skycoin, designed to solve the scalability and scalability issues of traditional consensus systems like Proof-of-Work (PoW) and Proof-of-Stake(PoS). Skycoin is a peer-to-peer digital currency and a decentralized internet infrastructure project.

The Obelisk algorithm is based on the concept of a “web-of-trust”, where each node in the network has a control over the consensus process. This type of consensus system allows the network to operate without the need of a single centralized authority, while still ensuring consensus across all nodes. All transactions and blocks are processed in an ordered, permissionless, and secure fashion which makes the Obelisk consensus algorithm highly desirable for applications and businesses which need transparent, efficient and secure blockchain applications.

The Obelisk consensus algorithm has a two-stage consensus process. During the first stage, the network creates a “web-of-trust” by connecting nodes to one another. At this point, nodes that are active in the network form a "trust" with other nodes in the web. This trust relationship is important for exchanging and verifying information, as no single node can control the system or sabotage it.

The second stage of Obelisk consensus is the actual creation of blocks. In this stage, all of the active nodes in the “web-of-trust” can create and validate blocks. The validity of the blocks created is verified by the nodes in the network, ensuring the security and integrity of the blocks. If any node tries to act maliciously and create invalid blocks, it will be rejected by the majority of nodes in the network.

Overall, Obelisk is an open-source, peer-to-peer consensus algorithm that provides an alternative to traditional PoW and PoS consensus. It has many desirable features for businesses and applications that need secure, efficient and transparent blockchain solutions. Additionally, it is a highly scalability algorithm that is able to handle large amounts of transactions with ease, which makes it an attractive consensus solution for those who want to build applications on the Skycoin blockchain.