Solo Hardfork Testnet Post Mortem Analysis

The following is an analysis of the Solo Testnet to fork to version v1.0.3.5
Hardfork scheduled for block 227001 (April 10, 2019)

Changes being tested:

• SECOR (Uncle Mining)
• 20 Second Blocks
• Full Bulletproof (Smaller Transaction size and fee)

A bulk of the analysis consists of blocks 1460 through 33562, approximately 8 days. ¹

Coinbase Statistics
Number of Blocks	32102
Coinbase Transactions	5890660
Emissions	5890629
Fees	30.5995

Making the blockchain more scalable

SECOR (Simple Extended Consensus Resolution, AKA Uncle Mining)² expands transaction throughput by allowing faster block times. SECOR further secures the network by reattaching otherwise orphaned blocks on top of the longest chain an rewarding the miner of the Uncle Block.

Uncle Statistics
Number of Blocks with Uncles	91
Emissions Due to Uncles	9170
Percentage of Blocks with Uncles	0.28%
Percentage of Emissions Due to Uncles	0.16%

Due to the adaptive reward structure emission rate is not affected by rewards to successful uncle and nephew blocks.³ The Uncle block reward is approximately 35.5% of the mined block reward. The following chart shows the reward amount in each block.⁴

Making Transactions Faster

Block times were successfully reduced from 60 seconds to 20 seconds while maintaining chain stability. Reward was adjusted to maintain the emission schedule.⁵

The network was stress tested with bursts of hashing power to test the difficulty adjustment for accurate block times and rate of Uncle Block production. No detectable difference in the rate of Uncle Block production was detected. The average block time was 20.02 seconds for the 32102 block test period.

Making Transactions Smaller and Reducing Fees

Full Bulletproofs make transactions smaller, thus reducing the fee for a given transaction while maintaining privacy and security.^6,7 Previously, a simple Bulletproof implementation was used. The change results in a fee that is approximately 4.5% of the previous fee.

Project Resources and Links

Repository: https://gitlab.com/solo-project/solo
Website: https://minesolo.com/
ANN: https://cryptocurrencytalk.com/topic/117663-ann-xsl-solo-a-secure-private-untraceable-pool-resistant-cryptocurrency

Social Media

Discord: https://discord.minesolo.com/
Twitter: https://twitter.com/SoloXsl
Reddit: https://www.reddit.com/r/soloproject

Notes

1. Blocks prior to 1460 did not include the changes, Blocks after 33562 experienced lowered testnet participation
2. https://nbviewer.jupyter.org/github/masari-project/research-corner/blob/master/secor/secor.pdf
3. Adaptive Reward based on historical data - emission formula slightly decreases block reward each block as a function of all coinbase transaction amounts previously generated.
4. Reward in testnet is different than mainnet, the mined block reward in block 227001 will be approximately 1/3 of the size of block 227000
5. Reward in testnet is different than mainnet, the uncle block reward will be 50% of the mined block reward
6. https://eprint.iacr.org/2017/1066.pdf
7. https://ostif.org/wp-content/uploads/2018/07/KudelskiBulletproofsFinal.pdf