Seven Reasons Behind a Delayed Crypto Transaction Confirmation
In a crypto Telegram group, I recently saw a question: “I have sent BCH to my wallet, but the confirmation is not showing up. Why is it so slow and how much time should I wait?” Let’s have a look at the most common reasons for delayed transaction confirmation times.
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The Seven Keys to Understanding Transactions
In the Cool Wallet S official Telegram group someone was asking a question about a BCH transaction that was “stuck”. How are blockchain confirmations made? And what causes them to sometimes get delayed?
1 — Block Propagation Time
This is one of the parameters you may underestimate, however, it is a really important one. When a miner discovers a new block, all other miners who are currently searching for the same block stop searching and concede it to other miners.
They check this block is valid and add it to their local copy of the blockchain. If the block is small, it will propagate fast across the network. For instance, how long does it take to download a 1 MB file? This is the “block propagation time” estimate for bitcoin.
Now presume that a block was found by two separate miners almost at the same time at opposite sides of the network. This block will simultaneously propagate from two sides. Both miners could have received their reward in BTC for the block.
But after two to five minutes, similar blocks will meet each other somewhere in the center of the network. When this occurs, nodes pick up the block that was created earliest, and reject the second one. All these operations take time and resources and affect confirmation times.
2 — Block Size
Block propagation time partially explains why this parameter affects the speed of confirmations. However, during the 2017 debates over the block structure, it became obvious that some people see block size increases as a plus.
For example, in the BCH network, miners can generate blocks bigger that 1 MB. This allows for more transactions. However, even when the network balance is working, it sometimes takes miners up to four hours to generate a new block.
This happened in the BCH network when it was beginning. The network increased the block size, but inherited bitcoin’s difficulty calculation rules, which led to enormously high block finding times. The issue was quickly patched by the main devs.
On the BTC network, a similar situation took place: the blocks became too small for the growing network of users in the winter of 2017-2018. The network wasn’t able to fulfill the public demand on the network. A huge queue of unconfirmed transactions became a reality.
The network did become stuck for weeks, leading to a panic sell and the price drop in 2018. The “normal” network fee became around $20-$50 USD. It rarely exceeds 30-50 cents.
3 — Number of Miners in the Network
Obviously, the more miners that are working within the network, the more people will try to take your transaction into a block. If your transaction is not confirmed after two hours, the issue may be that the network has no miners who want to process that given transaction or even the block itself.
Also, miners may use merged or offline mining, so the confirmations are slowed. These problems tend to affect newer blockchains.
4 — Transaction Fee Set by the User
At the moment, most crypto transactions cost cents. For example, in the BCH network, it costs between 3 to 30 cents. In the BTC network, that can be up to 90 cents. On the Ethereum network, it is 10 to 50 cents. If you want your BTC to arrive in the next block, the average fee will be 0.000005 to 0.0001 BTC. If you are happy to wait two to four hours, you can set the fee to 0.000001 or even 0.00000055 BTC.
The higher the fee, the faster the speed of confirmation. Most wallets will try to calculate a fee for you (Exodus) and others offer a choice of pre-defined options (Electrum, Mycelium).
Please note, in bitcoin you may use the Replace-by-Fee option in the Electrum wallet to increase the fee after the transaction has been sent.
5 — Speed of the Web
It is better to mine cryptos in places where no one can find your farm and ask questions. At the same time, putting a farm in an isolated village sometimes means very poor internet connections. In case the block is found in such a far-away corner of the network, it may travel very slowly.
Your own internet speed affects how quickly your wallet recognizes the confirmation. Also, what if your wallet itself needs a reboot? Try to close it and open it again to see if the TX history is refreshed or not.
6 — Mempool Bloat
The mempool is a special place where the network stores all the transactions in a queue. If the block size of 1 MB is not enough to cover all the transactions made over the last ten minutes, some transactions are left in the mempool.
People constantly send coins and the queue of unconfirmed TX’s may grow to a few days. The mempool itself has the built-in ability to reset every three days. This means that if your transaction missed the train, it will simply disappear after three days of waiting and the coins will return to your wallet. This poses a new risk–a zero-confirmation double-spend attack risk.
One way or another, the probability of such a scenario is very low and depends on many factors, including those covered in this article.
7 — Spam on the Network
It is not a big secret that the Bitcoin network has suffered what effectively are spam attacks. To perform one, you need to constantly send lots of small transactions with low fees from one address to another, under your own control. They often call these spam TX’s.
This possibility can be used as a pressure tool in wars against competing cryptocurrencies.
Have you recently had any issues with transaction confirmations? Describe them below.
Images by Jeff Fawkes, Pixabay