Cardano Steps Up PoS Security With Ouroboros Phalanx

As blockchain security becomes a central issue for regulators, institutions, and users, Cardano reveals a major evolution : Phalanx. This update to the Ouroboros protocol aims to neutralize grinding attacks, a vulnerability highlighted in Proof-of-Stake systems. Through this announcement, the network intends to reinforce its cryptographic foundations and assert its ability to anticipate the technical challenges weighing on decentralization.

A bulwark against grinding attacks on Cardano

Cardano, boasting its 115 million transactions, seeks to protect itself from a still little-publicized threat, but with potentially serious consequences : grinding attacks.

This type of attack allows an actor holding a significant share of ADA tokens, typically over 20 %, to manipulate the random selection process of block leaders.

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“The network randomly chooses who can produce a block. However, if someone controls enough ADA, they can grind different random seeds to maximize their chances of winning slots”, explains the development team.

This type of manipulation represents a structural risk for any Proof-of-Stake protocol, as it could allow a malicious actor to distort the consensus balance. To counter this, Phalanx introduces a verifiable delay function (VDF), which makes any grinding attempt much more resource-intensive. In practice :

• Each manipulation attempt requires a complex computation that takes real (and unavoidable) time to resolve ;

• Hackers can no longer instantly test millions of combinations, as each attempt becomes a tangible computational cost ;

• The selection of validators thus becomes much more robust and resistant to strategic manipulation ;

• This change is integrated into the core protocol and cannot be activated by a simple parameter adjustment: a hard fork is necessary for deployment.

By embedding this mechanism directly into the consensus protocol, Cardano adds an unprecedented layer of protection to its infrastructure. The approach does not aim to fix a past incident but to anticipate a still little-exploited threat using on-chain data and a proactive cryptographic response.

A strengthened protocol for a more efficient blockchain

Phalanx goes beyond securing the random selection of block producers. This update will also improve the overall efficiency of the network. “The update will bring faster transactions and better decentralization”, the announcement reads.

One notable change involves the evolution of random value generation, which will now span two epochs, about 10 days, making any single-point protocol manipulation attempt even more difficult. This multi-step approach increases the resilience of the network’s governance mechanism.

Moreover, the choice of deployment by hard fork underlines the scale of this transformation. Unlike simple parameter tweaks, this modification affects the core of the protocol, making implementation more complex but also more structural.

The adoption of the VDF within an advanced PoS algorithm like Ouroboros strengthens Cardano’s image as a blockchain focused on academic research and formal rigor. The project stands out in a landscape where many still prioritize speed over structural security.

This update could have significant implications. By consolidating its security architecture, Cardano sends a strong signal to the markets. The blockchain is ready to support more sensitive uses, notably in decentralized finance, stablecoins, or institutional projects. Phalanx also marks an implicit response to critiques often directed at PoS, sometimes seen as vulnerable to collusive behaviors or power concentration. With this evolution, Cardano attempts to close a gap… even before it is exploited.