About

Cardano is an open-source, smart-contract-enabled Layer-1 blockchain protocol. It uses a Proof-of-Stake consensus mechanism known as Ouroboros. Cardano is designed for various use cases, including finance, identity management, and supply chain tracking.

History

Cardano was founded in 2015 by Charles Hoskinson (former Co-Founder of Ethereum) and Jeremy Wood (former Executive Assistant at Ethereum). Charles is said to have disagreed with Vitalik Buterin's direction for Ethereum, wishing to create a privately-backed company to oversee network development. Thus, Charles and Jeremy left Ethereum and started a blockchain research and development company called Input Output Hong Kong (IOHK), now rebranded to Input Output Global (IOG). They had the vision of addressing the three challenges facing all blockchains: scalability, interoperability, and sustainability.

Cardano’s development is methodical and deliberate, prioritizing sustainability and stability over speed. Cardano’s roadmap consists of five eras that occur sequentially, though often in parallel, with most eras continuing to be iterated on:

Byron (Foundation)

• The Byron era arrived in September 2017 with the mainnet launch of Cardano and ADA after a multi-stage Initial Coin Offering (ICO). During Byron, Cardano operated as a federated network under the Ouroboros Classic Proof-of-Stake (PoS) consensus mechanism that only supported ADA transactions. Byron also saw the release of the Daedalus wallet developed by IOHK (now IOG) and the Yoroi wallet developed by EMURGO.

Shelley (Decentralization)

• Beginning in July 2020, the Shelley era focused on a shift away from being a federated network through progressive decentralization. This era introduced Ouroboros upgrades, such as Ouroboros Praos, which improved network security and made attacks on the network harder to achieve. Shelley also introduced stake pools, ADA delegation, and staking rewards.

Goguen (Smart Contracts)

• The Goguen era focused on the ability to build decentralized applications on the network. The era began in March 2021 with the Mary hard fork, which introduced NFTs and multi-asset (MA) support, allowing users to create “native assets” on the network. The era also saw the creation of the Cardano-specific Plutus smart contract language.
• In September 2021, the Alonzo hard fork occurred and enabled smart contract functionalities on Cardano. After the hard fork, users faced congestion issues when interacting with decentralized applications. In response, block size and script memory unit parameters were increased.
• Marlowe went live in May 2023. It is a domain-specific language (DSL) and set of tools that allows users to create and deploy smart contracts more easily without deep technical knowledge.

Basho (Scaling)

• The Basho era aimed to improve Cardano’s scalability through network upgrades, sidechains, and Layer-2 networks. In September 2022, IOG announced that the Vasil hard fork had been completed. Vasil introduced new capabilities, such as Plutus script upgrades designed to enable new network use cases, make transactions cheaper, and enable diffusion pipelining for faster block propagation.
• In February 2023, a hard fork brought new cryptographic primitives to Cardano, including more Plutus script upgrades by adding support for ECDSA and Schnorr signatures. These primitives allow for easier cross-chain interactions between sidechains.
• Interoperable sidechains such as Milkomeda C1 and the planned Midnight (developed by IOG) will scale the network by distributing transaction processing away from the main blockchain. Additionally, sidechains will provide opportunities to experiment outside the main blockchain by adding new features, such as account-based accounting systems and EVM compatibility. In January 2023, IOG released a toolkit for building custom sidechains, while IOG’s EVM-compatible sidechain launched on testnet in February 2023.
• The first version of the Hydra Head Protocol (Hydra) was launched in May 2023. Hydra is a Layer-2 network that aims to increase transaction speeds while minimizing transaction costs through state channels. State channels are offchain mini-ledgers between select participants, similar to Bitcoin’s Lightning Network.
• Mithril is a protocol scaling upgrade that employs a stake-based multi-signature scheme. In August 2023, Mithril went live on mainnet and produced its first snapshot. According to a blog post, Mithril aims to “solve chain synchronization, state bootstrapping, and trust issues in blockchain applications.” Mithril’s applicability extends to reducing the time and computation requirements for running full node clients and light clients and also enables sidechain deployment.

Voltaire (Governance)

• As of May 30, 2024, the Voltaire era is in progress and aims to make the network fully decentralized and self-sustainable long term. Specifically, Voltaire aims to implement fully onchain voting for (i) control over the project’s treasury via Funding Proposals (FPs) and (ii) network upgrades via Cardano Improvement Proposals (CIPs). After onchain governance is launched on Cardano’s mainnet, ADA tokenholders will control treasury disbursement and network upgrades rather than Input Output Global (IOG). Based on a commercially reasonable search, The Cardano Foundation and EMURGO hold all seven governance keys.
• Project Catalyst is an onchain governance experiment used to (i) submit project ideas through the IdeaScale site and (ii) vote to signal funding support for these projects using Cardano’s treasury. In each funding round, users can request a US Dollar (USD) value of funding to be paid in ADA, while ADA tokenholders register and vote on community-proposed projects. Fund 12, the most recent fund, is still ongoing, with no community-approved proposals as of May 30, 2024.
• In August 2023, SanchoNet, an onchain governance testnet for Cardano, was launched. SanchoNet is defined by CIP-1694 guidelines and serves as a sandbox for testing governance tools.
• In February 2024, Input Output Global (IOG) announced the release of Plutus V3 on SanchoNet, an upgrade to Cardano’s smart contract tooling developed alongside cryptography teams like MLabs. Plutus V3 introduces advanced Plutus primitives to enhance the toolkit available to developers for writing smart contracts on the Cardano blockchain and enable the creation of sidechain bridges. Hence, it aims to improve the developer experience of Cardano smart contracts by enhancing the network’s performance, throughput, smart contract size, and platform capabilities. A commercially reasonable search found no disclosures on an eventual mainnet release date for Plutus V3.
• In April 2024, Cardano unveiled the Chang hard fork, an upcoming network update that will deploy onchain governance on the network across two phases:
  • Chang Upgrade Number One - The first upgrade will deploy governance features on Cardano, initiating the technical bootstrapping phase outlined in CIP-1694. This upgrade will set the stage for decentralized voting and governance actions.
  • Change Upgrade Number Two - The second upgrade will introduce the final features of onchain governance, including delegated representative participation and treasury withdrawals.

By September 2024, the Chang Hard Fork went liveat block 10,764,778, ushering in the "Conway ledger" era.

In February 2025, Grayscale formally filed for a standalone Cardano ETF, the first U.S. product directly tied to ADA’s spot price, aiming for listing on the New York Stock Exchange. This was then followed by Digital Asset Treasuries (DATs) focusing on Cardano, mirroring trends first set by Bitcoin and Ethereum DATs.

On March 3, 2025, President Trump announced that the reserve would include Solana (SOL), Cardano (ADA), Ripple (XRP), Ethereum (ETH), and Bitcoin (BTC) aiming to make the US the "Crypto Capital of the World" and support industry growth.

In June 2025, the foundation introduced Originate, focused on verifying product authenticity and supporting industry certifications. According to the announcement, Originate supports custom integrations.

In July 2025, the SEC's Division of Trading and Markets granted "accelerated approval for the proposed rule change by NYSE Arca to amend NYSE Arca Rule 8.500-E (Trust Units) and to list and trade shares...of the Bitwise 10 Crypto Index ETF."

By September 2025, Cardano was integrated on NEAR Intents, allowing users to swap ADA across over 20 chains and over 100 assets. At the same time, the Mithril team published updates on the DMQ protocol and delivered a SNARK proving circuit prototype, supporting Cardano’s goal of secure cross-chain operations and efficient off-chain data verification.

In October 2025, Yoroi launched v6.0, integrating DexHunter and Minswap for streamlined user experience and broader DeFi access.