BEP-341: combatting MEV

BEPs/BEP-341.md

@@ -24,6 +24,7 @@
       - [4.2.2 Validator Set Switch](#422-validator-set-switch)
       - [4.2.3 Block Avoidance](#423-block-avoidance)
       - [4.2.4 Governable Number of Consecutive Blocks](#424-governable-number-of-consecutive-blocks)
+      - [4.2.5 Combatting MEV through Linearly Increasing System Reward Splits](#425-combatting-mev-through-linearly-increasing-system-reward-splits)
   - [5. Incentive Fairness Analysis](#5-incentive-fairness-analysis)
   - [6. Security Analysis](#6-security-analysis)
   - [7. License](#7-license)
@@ -84,14 +85,23 @@ To prevent fewer than 1/2 of the nodes from controlling the entire network, bloc
 #### 4.2.4 Governable Number of Consecutive Blocks
 When n=1, it is equivalent to disabling the feature of consecutive block production, while significant optimization is observed when n belongs to the range [3,5]. Currently, the range for the value of n is set to [1,9] but except 2.
 
+#### 4.2.5 Combatting MEV through Linearly Increasing System Reward Splits
+As the consecutive period in which a single validator gains priority in block production extends, it may facilitate MEV extraction, potentially leading validators to include more transactions in the later blocks they consecutively produce. To constrain validators to promptly package transactions, within a validator's consecutive priority over n blocks, the transaction fees' split to the SystemRewardContract will increase linearly with block number.
+Assuming minRatio and maxRatio are the minimum and maximum split ratios, respectively, the split ratio remains at minRatio when continuous block production is disabled. Once continuous block production is enabled (i.e., when n > 1), the systemRewardRatio is calculated as:
+<div align="center">
+<img src=./assets/bep-341/4.2.5-1.png width=100% />
+</div>
+as shown in the following picture:
+<div align="center">
+<img src=./assets/bep-341/4.2.5-2.png width=75% />
+</div>
+
 ## 5. Incentive Fairness Analysis
 Within a single epoch, tail validators have fewer block-producing opportunities, but the allocation of priority rights is unbiased and cannot be manipulated. Therefore, from a statistical perspective, it is fair.
 ## 6. Security Analysis
 This BEP relies on BSC's Fast Finality feature. If Fast Finality fails, it may result in the following issues:
 1. Nodes intentionally hide mined blocks, potentially leading to longer short-term reorganizations. 
 2. The probability of finality for transactions increases, requiring waiting for 2/3 validatorN * n + blocks. 
 
-In addition, as the consecutive time during which a single validator gains priority in block production increases, it may make MEV extraction easier.
-
 ## 7. License
 The content is licensed under [CC0](https://creativecommons.org/publicdomain/zero/1.0/).