Following network security incidents, Ethereum Classic has implemented MESS (Modified Exponential Subjective Scoring), a novel approach to enhancing chain security.
What is MESS?
MESS adds an additional layer of protection against chain reorganizations by making it exponentially more difficult to reorg recent blocks. It works by requiring increasingly more work to replace recent blocks.
How It Works
MESS assigns a "gravity" score to chain tips based on:
- The length of the chain segment
- How recently blocks were produced
- Total accumulated work
Longer reorganizations require proportionally more work to succeed, making attacks more expensive without changing the fundamental proof-of-work consensus.
Benefits
- Attack Resistance: Makes 51% attacks significantly more expensive
- No Centralization: Doesn't rely on checkpoints or trusted parties
- Preserves Finality Model: Transactions still achieve probabilistic finality through proof-of-work
Implementation
MESS was activated through a client update, not requiring a hard fork. Node operators upgraded their software to enable this protection.
This represents a pragmatic approach to security enhancement while maintaining ETC's commitment to decentralization.