X25X – PoW

In-house, GPU Mining Algorithm

To protect and enhance the decentralization of the SINOVATE blockchain, a leading-edge custom proof-of-work hashing algorithm was innovatively developed and implemented. The X25X algorithm is a brand new algorithm best suited for GPU mining. It is also ASIC, FPGA, and Quantum resistant with the addition of SWIFFTX to the algorithm chain. Ultimately, the X25X hashing algorithm prevents large mining operations or farms from dominating the SINOVATE blockchain. It is praised for being a very secure, fair, decentralized, and highly accessible method by which to mine SIN coins. 

The X25X is an excellent example of how SINOVATE is evolving blockchain technology.


The purpose of the original X25X whitepaper was to design a proof of work algorithm that could provide the best possible combination of the following points:

  1. Make ASIC and FPGA design much more difficult and expensive
  2. Allow GPU optimised miners to be developed quickly
  3. Allow GPU miners to have maximum efficiency
  4. Add quantum resistance
  5. Use components which are proven, industry standard algorithms, like sha-2 and sha-3, for best security


Being X25X, a chain of well-known hashing functions, coding a GPU miner is mostly a work of assembling open-source code. X22i currently has many implementations, both private and open source, and the missing stages to reach the full X25X chain are all available as open source as well (except the shuffle stage, which is new, but is simple to implement on GPU code).

Many overly-optimized sources will not work or need to be heavily modified, as they do not provide full output for all the algorithms in the chain. This is good because it should decrease the hash rate difference between private and open source miners.
Quantum resistance

A big concern in the crypto community, linked to centralization, but with even worse consequences, if ever exploited, is the possibility of “breaking” the hashing algorithms used in the current coins with a quantum computer. A particular entity with access to this kind of hardware could be able to achieve a considerable efficiency advantage over the rest of the miners, or even being able to make an “extreme 51% attack”, reverting a big chunk of the chain and introducing the possibility of double-spending, and total control of the blockchain.

To address this issue, X22i introduces a post-quantum element in the chain, SWIFFTX, with lattice-based cryptography. Of course, this component is also present in X25X.

The threat of quantum computers while present is not yet something active though continually evolving, as seen with Google’s recent advancements.

The consequences of a quantum computer being able to break Sha-256 (the algorithm used by Bitcoin) would be far-reaching beyond cryptocurrency with most websites and other internet traffic using the same or similar encryption methods. SINOVATE will continue to monitor this situation and add further protection if necessary, with our ever-evolving algorithms.

“Its main attractive features, among others (including no known quantum attack at the time this paper is written), are probably rigorous asymptotic security analyses and asymptotic efficiency.”

 An active ASIC, FPGA, and the Quantum resistant algorithm is essential for the mining community.  It defends the blockchain against attacks as described earlier. 

Mining hardware for SINOVATE is readily available and offers a range of entry levels for participants that are as inexpensive as the vast array of GPUs available. This means the hardware used to mine the coins is readily available and guards against the centralization threat from specialized ASIC and FPGA manufacturers.

X25X is the natural evolution of X22i, the previous algorithm used for SUQA cryptocurrency before rebranding to SINOVATE with further improvements on ASIC and FPGA resistance. It aims to help rejuvenate and sustain the GPU mining community and enhances the decentralization of the network. 

X25X follows the goal of ASIC and FPGA resistance by implementing multiple additional features over the outdated proof-of-work algorithm chains like X11 that are now dominated by ASIC miners.

X25X raises the memory requirements of X22i by a factor of five. This is not a problem for CPU and GPU mining but much harder for FPGA and ASIC. They need to either use commodity RAM (giving them no advantage over CPU and GPU) or implement more embedded internal RAM, increasing the chip space needed. 

Another advantage over the classic proof-of-work algorithms is in having a much longer algorithm chain. Twenty-five algorithms make up the full chain, which again creates the need for more chip space to implement. This is hugely cost-prohibitive for FPGA and ASIC manufacturers.

Finally, the more excellent plan evolving around X25X is to increase the chain size with further hashing stages (X27mh, X3XX, ) to be released periodically. This approach forces the chip designers to revise the design often, meaning more cost and less time for using the chip for mining. 

Moreover, making the algorithm chain progressively longer addresses the concern of future FPGA chips growing to accommodate the whole X25X chain on a single chip.


Difficulty adjustment algorithms have been designed, tested, and implemented to improve the way in which the mining difficulty responds to fluctuating network hash power, however small or large. 

More recently, more advanced difficulty adjustment algorithms have been released and adopted after meticulous testing phases.  SINOVATE has been at the forefront by integrating the latest difficulty algorithms into their code protocol.  In particular, the LWMA Difficulty Adjustment Algorithm is being used to solve 51% attacks and functions as follows:

It estimates the current hash rate in order to set the difficulty to get the correct solve times by dividing the harmonic mean of the difficulties by the Linearly Weighted Moving Average (LWMA) of the solve times. It gives more weight to the most recent solve times. It is designed for small coin protection against timestamp manipulation and hash attacks. The basic equation is:

next_difficulty = harmonic_mean(Difficulties) * target_solvetime / LWMA(solve times)

REORG Depth Solution & Fork Rejection

Another method to counteract 51% double-spend attacks is known as Default Maximum Reorg Depth Solution.  A sufficient number of trusted nodes or computer servers communicate with each other to prevent a forked chain from becoming maliciously accepted as the “honest” chain.”  

This is achieved by setting a maximum number of preceding blocks from which forked chains can be formed, either valid or malicious.  A low maximum reorg depth solution is not recommended as it will deter valid chain forks. 


There is a necessity for an agile, secure, ASIC and FPGA resistant, memory optimized algorithm that is prepared for constant dynamic decentralization alignment against ever changing advances in computing technology. 

An evolving world requires adaptable algorithms and that is why SINOVATE will keep adding innovations and new algorithms every 9 months to stay away from the threat from the large ASIC and FPGA hardware companies and, if it emerges on a practical scale, the threat of Quantum Computing.

The cross-functional algorithm team work using Agile project practices and are in constant communication, despite being all over the globe.  This allows a nimble software development cycle with adaptive planning to allow the team to keep ahead of any challenges and can react quickly to change.

Blockchain specifications and Block rewards



2 minutes

Block Size


Difficulty Retarget



Always less than 800 million infinitely



The efficiency and reduced heat profile of the X25X hashing algorithm aids miners and proves that mining operations do not have to maximize power consumption and heat output to compete and to be ASIC/FPGA/Quantum resistant.  For larger miners this can mean easier scalability with less cooling and ventilation requirements.