Preconfirmations

Inclusion and execution preconfirmations are essential mechanisms in blockchain transaction management, each serving distinct roles to enhance transaction reliability and trust. Inclusion preconfirmations ensure that a transaction will be incorporated into the blockchain, offering a preliminary guarantee that the transaction will occupy a block. This mechanism primarily focuses on the transaction's entry into the block and may involve conditions such as block space availability, transaction fees, or ordering.

In contrast, execution preconfirmations provide assurances that a transaction will not only be included but also guarantee the settlement outcome once executed and included on chain.

Both preconfirmation types leverage various economic incentives and penalties, such as collateral, insurance or slashing, to uphold their guarantees and mitigate associated risks.

Inclusion Pre-confirmations

• Definition: Pre-confirmation that a transaction will be included in a block.
• Focus: Ensuring that a transaction makes it into the blockchain.
• Guarantees: Guarantees inclusion in the blockchain.
• Verification: Typically requires less intensive verification.
• Examples of Mechanisms: Optimistic Pre-confirmations, Pessimistic Pre-confirmations.
• Conditions: May involve conditions related to block space, fees, or order.
• Economic Incentives: May involve collateral or slashing for not including transactions.

Execution Pre-confirmations

• Definition: Pre-confirmation that a transaction will be executed once included.
• Focus: Ensuring that a transaction is executed correctly and without issues.
• Guarantees: Guarantees settlement of execution of the transaction.
• Verification: May require more intensive verification to ensure execution correctness.
• Examples of Mechanisms: Validity-based Pre-confirmations, Unconditional Pre-confirmations.
• Conditions: May involve conditions related to the state, computational resources, or correctness.
• Economic Incentives: May involve economic penalties for failed execution.

Exotic Preconfirmations and Where NOT to find them

• Optimistic Pre-confirmations:

  • Assumes trust by default
  • May involve collateral or slashing conditions if not honored

• Pessimistic Pre-confirmations:

  • Requires explicit verification and guarantees
  • Involves intensive computational checks or multi-party agreements

• Execution Tickets:

  • Validators' roles are separated
  • L1 proposers can opt into pre-confirmations and sequencing through a side protocol
  • Could be implemented as an AVS (Eigen layer)

• Collateral-based Pre-confirmations:

  • Relies on economic incentives and penalties (e.g., slashing of collateral)

• Validity-based Pre-confirmations:

  • Requires real-time verification and validation mechanisms

• Conditional Pre-confirmations:

  • Tied to specific conditions or outcomes
  • Transaction inclusion depends on particular state or circumstances

• Unconditional Pre-confirmations:

  • Promises execution regardless of future states or conditions
  • Requires strong guarantees

Pre-confirmation Mechanism Matrix

Mechanism	Description	Verification Method	Conditions/Incentives	Roles/Implementation
Optimistic Pre-confirmations	Assumes transaction will be included based on trust by default	Based on trust, may involve collateral/slashing	Trust, collateral, slashing penalties	Validators, possible AVS implementation
Pessimistic Pre-confirmations	Involves explicit verification and guarantees before pre-confirmation is valid	Intensive computational checks, multi-party agreements	Verification and validation	Validators, requires multi-party agreement
Execution Tickets	Separates validators' roles, allowing L1 proposers to opt into pre-confirmations and sequencing	Side protocol implementation, AVS (Eigen layer)	Opt-in mechanisms for L1 proposers	L1 proposers, AVS implementation, decoupled from validators
Collateral-based Pre-confirmations	Relies on economic incentives and penalties (slashing of collateral)	Economic incentives and penalties	Slashing of collateral	Validators, economic penalties
Validity-based Pre-confirmations	Relies on real-time verification and validation mechanisms	Real-time verification and validation	Inherent transaction validity	Validators, real-time validation
Conditional Pre-confirmations	Tied to specific conditions or outcomes for transaction inclusion	Condition-specific verification	Specific state or set of circumstances	Validators, conditional mechanisms
Unconditional Pre-confirmations	Guarantees transaction execution regardless of future states or conditions	Strong guarantees	None (unconditional promise)	Validators, strong guarantee mechanisms

This table summarizes the key aspects of each pre-confirmation mechanism, highlighting their descriptions, verification methods, conditions or incentives, and roles or implementations involved.