Bitmark is a decentralized Level-1 (L1) blockchain platform that uses 8 different proof-of-work (PoW) algorithms to secure its network and verify transactions. Miners who contribute computing power to validate transactions and add new blocks to the blockchain are rewarded with Bitmark coins.

Bitmark’s block rewards, which are given to miners, change over time through a series of epochs. Initially, Bitmark’s reward system was similar to Bitcoin and Litecoin, but it introduced a quartering of rewards between the traditional halvings. The first few block reward epochs and their changes are as follows:

1st epoch, 20 tokens per block
2nd epoch, 15 tokens per block (first quartering)
3rd epoch, 10 tokens per block (first halving)
4th epoch, 7.5 tokens per block (second quartering)
5th epoch, 5 tokens per block (second halving)
6th epoch, 3.75 tokens per block (third quartering)
7th epoch, 2.5 tokens per block (third halving)
8th epoch, 1.875 tokens per block (fourth quartering)
9th epoch, 1.25 tokens per block (fourth halving)

On June 6th, 2018, the Bitmark community made three major changes:

1. Added 7 more PoW algorithms, allowing merge-mining on all algorithms.
2. Adopted the Dark Gravity Wave mining difficulty adjustment function.
3. Implemented the Coin Emission Modulation (CEM) algorithm to reduce block rewards based on the current hash rate compared to recent peaks.

The CEM algorithm adjusts block rewards by comparing the current hash rate to the peak hash rate (the highest daily hash rate in the past year). This results in an emission scaling factor (ESF) that determines whether the block reward is given in full or reduced proportionally. If the current hash rate is at or above the peak, the full block reward is given. If it’s below the peak, the reward is reduced, but at least half of the total reward is always given.

Each PoW algorithm operates independently and rewards are set for each without regard to the other algorithms. This means that emission thresholds and epoch changes will happen at different times for each algorithm. The current hash rate is calculated based on the previous 90 blocks for each algorithm, and the peak hash rate is determined by looking back at the previous 32,850 blocks (representing one year of data).