Nodes – full, lightweight, SPV

Full Node

Any computer connected to a cryptocurrency network can be said to be a node. For example, a Bitcoin node is a computer connected to the Bitcoin Network. Nodes that fully validate every block and transaction given to them are known as full nodes. These nodes check the transactions against the consensus rules. The following are some of Bitcoin’s consensus rules:

  • No double-spending on any transaction output.
  • Transactions and blocks must be in the correct format.
  • Blocks may only release a certain number of bitcoins as a block reward.

Consensus rules cannot be broken. Any block or transaction that does not follow the consensus rules are rejected by the full node and won’t be included in the Blockchain. Networks are supported by the Full nodes accepting blocks and transactions from other full nodes. These are then validated and relayed back to other full nodes to be validated by them. Since nodes are trustless, they will reject ANY block or transaction that doesn’t follow the consensus rules no matter if every other node on the network says they are valid.

Running a full node means you must have a copy of every transaction and block that has ever taken place on the blockchain. So, to run a full node, a person must download that entire file to his/her computer. Since there is not one single point of failure in the network, the blockchain cannot be controlled by one single entity, nor easily compromised. Therefore, increasing the number of nodes in the system would result in a more decentralized and trustless network.

Lightweight Node

Full Nodes are also known as “Lightweight Nodes,” and sometimes called “Lightweight Clients.” SPV (Simplified Payment Verification) methods allow Lightweight nodes to verify transactions without downloading the entire blockchain. Full nodes assist lightweight nodes by allowing them to connect and transmit their transactions to the network and will notify them when a transaction affects them. The only information a lightweight node needs to download to their computer is the headings of all blocks on the blockchain, which dramatically reduces storage requirements and is far less than that of a full node.

Lightweight nodes would not be able to connect to the cryptocurrency network, which could lead them to use centralized services instead, so this relationship is a needed service. Important to mention, SPV nodes put all their trust in full nodes to ensure that blocks and transactions are validated right and follow consensus rules.

What are the advantages of running a full node in comparison with a lightweight node/client?

This scenario is from and has to do with the security of the SPV nodes. Something to think about!

A lightweight client cannot even check for itself that a confirmed transaction is valid. It has to trust that miners will not spend time confirming invalid transactions.

If you have an SPV client and I am an evil miner with a substantial amount of mining power, I can make a transaction with a nonexistent input (essentially creating coins out of thin air), and include it in a block I mine. This block won’t be accepted by any full node, because they will have a complete transaction register and will know that the input is nonexistent, but your SPV client would accept it. If I then mine some more blocks on top of my bogus block, your SPV client will think that transaction has several confirmations. This will work particularly well if I can mess with your network connection so that you can’t connect to any full nodes except for evil nodes controlled by me.

Of course, this attack is relatively costly for me, since I have to spend mining power that could otherwise generate legitimate coins, but maybe it is worth it if I can buy something valuable from you and pay with fake coins. So if you are in the business of selling high-value goods, you might very well consider it worthwhile to have a full node.

About the author

Born in Illinois and the third oldest child of 10 children. Gail learned many lessons in life that would serve her well in her future. Patience, sharing, compassion, understanding, love, and acceptance were a way of life. Family is significant to Gail as a mother of three herself.
Gail lives by the motto "live and let live," and she takes pride in helping others. Educated, yes, but believes life is the best teacher and learning depends highly on an open mind.


  1. Interesting to read about the full node and the lightweight node. Its very clear witch one is the safest way to go to be more secure at the end. I never noticed any difference so fare , but also have not used it enough to be aware of. Its a good lesson witch will come handy once we are opening our Compumatrix business .

    1. Gail, you are fantastic, the way you express the information that you overstand is incredible. This is so important to know and thanks for sharing this important information. It really excites me the journey that we are on. Every time information is shared like this it gives me a rush. We are so grateful, to admin, staff, Henry for helping us keep our heads, and dream in tact for what is to come to fruition. We are on our way, Hoooray!!! Many Blessings to all.

  2. I agree with Gitta , Interesting reading Gail about the full node and a light weight node. I know that to be real safe is to run your own node. I do have to do some more research on running your own node and where to get one and how to set it up. Seems interesting as well.I think it is well worth it for people to run their own node if they do a lot of transactions . That will come sooner that later I think.

  3. I never heard of Lightweight nodes before. It is interesting especially the reference to the “evil” miner. It always amazes me the lengths someone would go through to try to take advantage of others. In the case you cited, the miner would have to spend a lot of mining power just to pull this off while they could have been mining legitimate coins.

  4. Wow, good to have our “node” knowledge expanded – for me, a node was something at times I was always trying to find one to connect to in order to be able to open my Dex account. Now, learning there is certainly a lot more to the idea of nodes, and sounds like a full node is a better choice over a lightweight node to avoid any corruption or evil doings of which it always seems there is someone willing to be evil.

  5. great read Gail — it is beyond just a nice thought — when reading your blogs there is so much great info and honestly looking past the actual blog and seeking the financial parts and putting that with the terminology of the Crypto world it is awesome in my learning curve — and yes will read this many times — it is that good — thank you —

  6. Now we get an understanding of the importance of our nodes in Compumatrix to be working correctly, and why they are essential. Gail, I keep thanking you for breaking information down in sections, for us to somewhat understand each part that comes together to make a digital crypto company work, quickly and efficiently, in its entirety. I have to print all the post to read them and save to a file box all that is pertaining to our business. These post I will read again and again and use them as references. I am thankful we can operate our Compumatrix CDAP without fully understanding everything, but we have a working knowledge for now and will learn as we work our businesses.

  7. Gail thank you for simply explaining the differences in nodes. While listening to my daily YouTube videos I have many talks discussing buying a node and other node topics. Your blog will help me understand those talks better. This just opens up more questions in my mind about how nodes will be incorporated into Compumatrix. That will be a conversation for another day!

  8. Fresh news for most us on NODES. Lots of new stuff to learn about especially how it all works. The whole Nodes thing has been a bit of a mystery to me, at least the details how they work. I get the verification process with other nodes when processing a Bitcoin transaction and the interactions with BlockChain.

    My nephew has a full system he wants to sell but the computer needs to be replaced with a high performance model. Might want to take a look at it in the next week or so. It’s all quite a process.

    I wonder how I can become a node? Could being a Node be in my future? (lol, I think the answer will be more clear, soon!)…..

    Thanks Gail appreciate the blog.

  9. Thank you for this blog post, Gail! I knew generally what nodes were, but I did not know the difference between full nodes and lightweight nodes. Now that I know this information, if I were to operate a computer as a lightweight node, I think I would be a little scared that the full node I am using to complete my transaction has the power to take advantage of me if they wish to do so. Although, I do think operating a computer as a lightweight node is more appealing because there is not as much storage needed as opposed to if operating a computer as a full node.

  10. yes as stated earlier am back learning and the second time thru it struck me how important it actually is in the crypto world to be decentralized and where only the people involved in the transaction having access to that transaction and if there are discrepancies in the full node then it is kicked — but lightweight can be taken advantage of because it doesn’t go far enough into detail ?? think i am understanding better ? hope so —

  11. Great read Gail…Really need this and will have to re-read it multiple times to really get a grasp of how it works and a better understanding of the node system. This break down of “Nodes” is very descriptive and well explained. Thanks again for the well written description.

  12. It seems quite apparent that NODES are a very important factor for digital transactions and group interaction. This helps me understand that talk in our Compumatrix Chat about nodes and the upcoming benefit they are going to be in us having real time data available to our group without the downtime that we have experienced off and on up to this point.

  13. Good article to investigate further. In my research I found that there are a number of points to consider regarding Full Nodes. 1, You need a computer with at least 200 Gigs of free disc space. 2. Minimum Read / Write speed of 100 Mb/s. 3. 2 Gigs of memory (RAM) 4. You need a good high speed internet connection with minimum Upload speeds of 50 Kilobytes per second. 5. A Full Node will use 200 Gigs or more per month to upload, 20 Gigs to download per month, and 195 Gigs to start running your Node. There are a number of other points to consider, but this may help understand a bit more on the Full Node. I do believe there will be greater understanding and training of how we will be able to assist.

  14. Thank you Gail and also everyone else for the great comments revolving around the discussion of nodes. My next question was going to be what types of computers and cpus/ram would be required to run these nodes. Then I saw Hendriks message and quickly made some notes. Keep these productive conversations going.

  15. This is an area that I lack full understanding in so this article is a good find for me. It is timely too since the Announcement today about how Compumatrix members “…will all be given a link to join in. We will all be nodes!” I will read this over again and try to understand nodes better. But even without a full understanding of what all nodes do, I realize that this development will result in the CDAP being fully decentralized! That is very exciting from an operational standpoint!!!

  16. after reading Gails latest blog on uncles n orphans — and putting this with that –it is so very important for Nodes to be and it fascinates me to see the intricacies of the Blockchain and how so many different parts are involved and how Exact every piece has to be or it is not accepted — and seriously much more today do i understand the decentralization factor — thank you again — great replies n blog —

  17. More lights to understand. That, the Full Node really provides total and full security to the Cryptocurrency Network. For a complete transaction from the Blockchain. Has to be enhanced by all the Nodes connected together. Also, Incredible to learn that verification and confirmation is done both ways, before a transmission is permitted. This serves as the most protected Decentralized services ever.

  18. Each time we learn more and more about this crypto ecosystem.
    I knew about the full node concept, but not about SPV (Simplified Payment Verification), I do now.
    Compumatrix will ask for each member to become a Compumatrix node.
    This is good news for it will keep our system always fast and running.

  19. As I understand it we will all be full nodes. We have to download and sync a ton of information so I’m sure that is right. Plus I believe Erline did say that too. Whatever it is I’m ready! Bring it on and I node I can handle it!! lol

  20. This is really good to know it is like the corruption in the chain. I had no ideal there was a lightweight node or that it was called that. Getting educated on this is great stuff to know there are more rules then I ever thought with the transactions of the nodes.

  21. Thank you Gail, there was a great increase in information about nodes,full nodes, light weight SPV (simple payment verification)there is a relationship between full nodes and lightweight nodes, if this is not the case, then lightweight nodes is not able to stay connected to the cryptocurrency. It is important to understand all of these nodes and how the nodes are being used in compumatrix.It needs to be understood more now.

  22. Thank you Gail for the very informative blog regarding the nodes. I appreciate how you make things so easily understood. I have been wondering what a node is and how it works. I need to read it more times to be able to grasp exactly how I will be able to utilize it in my Compumatrix business.

  23. Nodes are a subject I have almost tried to avoid except when absolutely necessary. But once you begin to understand how important it is that nodes work correctly, you can see why it is worth your time to understand how they can make our crypto world so much easier to work in. Like so many things we deal with, I will have to read and re-read this to really understand the how and why of it all. Fortunately, there is always a place to go for the answers.

  24. I read your blog last night, Gail, but I had to read it again today for better understanding about the nodes. Thank you for this important information and for the comments too from the members who are in the know; very educational for all of us. I hope we all get the full nodes for the Compumatrix business to protect our accounts from unscrupulous persons.

  25. back for more understanding of nodes and the whys and wherefores of this part — so fascinating the likenesses twix the Crypto world and terminology used and the international gaming world and the likenesses just fascinating but if gonna get better have to learn — thank you again for great info n explanation —

  26. The part of the blog that mentions that “there is not one single point of failure in the network, the blockchain cannot be controlled by one single entity, nor easily compromised,” reminds me of the blog that explained 51% attack. I realize though that the focus of the block is about nodes and not hacks.

  27. The graphic image is like an image of a bright constellation. The bright spots within the graphic would appear to represent the nodes at various points within their force field. As in stars, the nodes would not necessarily be confined to a specific location within the force field, but move around it.

  28. now after reading more blogs and staying abreast in discord and understanding already the absolute need for security on anything business wise on computer — having Full Nodes make the Biz much more secure from issues and as Compu becomes front page news — we have to be as secure as we can be — great read still —

  29. Gail does write some fascinating blogs. I cannot claim to know anything or even understand nodes. However Gail’s piece has given some excellent information. When you are dealing with business and finance security is the number one consideration. Our business is no different and we need to be vigilant at all times.

  30. Very interesting article and education for us about what Nodes are really in computer language.This gives us a better insight to understand and learn what Nodes are,and how to make use of it.We are happy to have learnt about Nodes just in time for launch of Compumatrix.

  31. Thank you once again for a very much for another Educational Blog.Interesting differences between the Nodes and weakness of the Light node as opposed to the Full node. Learnt about SPV too.Believe Compumatrix to have it’s own node which is a plus.Earlier on I knew only of Human body nodes ,Plant notes and Chemistry nodes. Now I know more .

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