I think the best solution here is to simply note everyone's payments in a database and add them to subsequent weeks, and then process a payment once a month, for a couple of reasons.

Trying to get everyone to accept an altcoin, which many will be unfamiliar with and many will want to exchange immediately for bitcoin, is going to cause you a massive headache and many will be annoyed about having to eat the exchange and transfer fee to exchange back to bitcoin.

Sending some outputs as low as 4000 sats is just causing people to have to consolidate loads of small inputs and lose even more in fees in the future. You would be saving them a lot of money by sending payments once a month instead of once a week.

Once we hit the next difficulty retarget, the difficulty is going to drop by around 20% which will result in a speed up of the average block time which should lead to a reduction in the mempool.

I can also confirm that I cannot access their clearnet site but their Tor site is working normally. They appear to be dealing with a number of other users who are having the same issue as you, where they have made a deposit which has not been credited:


It is very unlikely this is a scam attempt. Simply PM their account above and wait for their resolution.

There are a number of methods you can use to trade bitcoin in person for cash while still maintaining your privacy and security. I've done a number of trades with complete strangers which have gone smoothly.

• Only trade with someone in person who has a history of numerous trades and plenty of positive feedback.
• There is no requirement to share any personal details with them whatsoever. Simply pick a time and place to meet, and some sort of physically identifying information (I'll be wearing a blue Yankees cap, for example).
• Meet in a public place with plenty of other people around. You can also go for somewhere with lots of CCTV if you like such as a big shopping mall or a major travel hub (such as an airport). You can also meet directly outside a bank which either the BTC buyer can withdraw cash from immediately prior to the trade, or the BTC seller can deposit cash to immediately after the trade. Doing this eliminates the risk of counterfeit bills.
• Bring a friend with you. If legal in your jurisdiction, bring something for self defense.
• Only take with you the exact amount needed to complete the trade, be it in fiat or BTC.

Yeah, with the mempool filling up like this and the mempoolminfee increasing to around 16 sats/vbyte, OP's first transaction paying 10 sats/vbyte is now starting to be purged from some nodes. Looking it up on various block explorers comes up with around a 50/50 split of nodes which still have it in their mempool and nodes which have purged it. Since the first transaction is now being purged, you should be able to double spend it successfully which you were not able to do before while it was still in the mempool.

Bear in mind however that the current fee needed for a fast transaction is around 200 sats/vbyte. Given your transaction has 28 inputs and a size of 4,174 vbytes, you would end up paying more than 0.008 BTC in fees, which is around 40% of the combined value of all your inputs.

If you want more security than a standard software wallet without having to go through the additional 2FA fees and the higher transaction fees associate with multi-sig, then I would suggest using a hardware wallet such as a Ledger or Trezor device. While not exactly the same, it is still far superior to a standard software wallet in terms of keeping your private keys secure. Although there is obviously an initial expense with buying one, given TrustedCoin's fee and multi-sig fees, by the time you've made >20 transactions it will have worked out cheaper overall than a multi-sig set up.

All Trezor models and any other hardware wallets based on Trezor such as the KeepKey are vulnerable to this exploit.

The Trezor T is still vulnerable to this attack. If you use a strong enough passphrase, then although your seed phrase can be extracted your coins cannot be stolen since they are further protected by your passphrase. If you use optional SD card encryption, then the attacker would only be able to extract your encrypted seed phrase and would have to brute force the decryption password, which is presumably impossible. (I'm not entirely sure what encryption method Trezor uses or the strength of the decryption key they generate, but I assume it is strong enough to withstand brute force attacks).

You cannot use an existing non-2FA seed phrase to create a 2FA wallet. If you want to use a 2FA wallet, then you need to create a brand new 2FA wallet from scratch, write down and store securely the new seed phrase it generates for you, and then send all your coins from your existing wallet to your new 2FA wallet.

Note that since 2FA wallets are multi-sig, any transaction you make from this wallet will be much larger than from a standard wallet, and will therefore incur higher fees. While usually this may not be much of a consideration, given how full the mempool is at the moment and how expensive fees are, you will end up paying significantly more for all transactions from your 2FA wallet than for similar transactions from your non-2FA wallet. (And there is TrustedCoin's fee to pay on top of all that, as well.)

No, they didn't.

Every site/exchange/company/person/app/etc. which requires you to deposit coins before you are allowed to withdraw is a scam. Full stop. No exceptions. They are trying to scam you.

"Some girl" you don't even know just gifted you $43,000? Come on. Use your head. It is a fake platform that can display anything they want it to display. There is no bitcoin. They ask you to deposit, and if you are stupid enough to do it, then they will say the activation failed and you need to send more, or you only activated a low tier and you need to send more, or if you wait a week and then send more you'll get even more in return, or anything that will get you to deposit more. As soon as you stop depositing more, they will move on to their next victim.

Don't send them anything. You are being scammed.

In case you still don't believe me, the entirety of the text on the front page of their website is plagiarized from this exchange: https://cex.io/
Here is a list of sites which are completely identical to the one you are using, all trying to pull off the exact same scam:
https://www.skyescrm.com/
https://www.haxbit.com/
https://www.bitprotrade.com/
https://trader-bull.com/
https://trade.surf/
https://mybitfx.com/

You should start with bitcoin and bitcoin alone. Most other coins are abandoned, vaporware, scams, or some combination of these three.

You absolutely should not put your last remaining money in to bitcoin. The price could drop by 20% tomorrow. Would you be prepared if this happens?

You will not become rich by buying $400 worth of bitcoin. The days of people becoming millionaires from scratch with bitcoin are over.

Binance is a company, which have both their own website and their own app. If you decide to buy there, you will first need to register for an account, then undergo KYC procedures which will involve verifying your identity by sharing your personal information and copies of your ID with them, then fund your account with a bank transfer or other deposit method, then exchange your fiat for bitcoin, and finally withdraw your bitcoin to your own wallet. If you don't want to share your personal information and ID with complete strangers, then you will need to use a peer to peer exchange instead.

This is optional. There are two options when using a passphrase with Ledger devices:

• Attach to secondary PIN. The passphrase is stored on the device, and when you enter the secondary PIN on start up it will open your passphrase protected wallet.
• Set temporary. Nothing is stored on the device, and you must enter the passphrase each time you want to use it.

I don't particularly like the "attach to secondary PIN" option for a few reasons. The first is as you've said - storing the passphrase on the device itself is a security risk and negates part of the reason for using a passphrase in the first place. Second, most people who use it are probably only using a single passphrase, when multiple different passphrased wallets are the best option in terms of security. Finally, a lot of people who use passphrases neglect to back them up properly by writing them down and storing them separately from their seed phrase. If you haven't backed up your passphrase then although you should never rely on your memory as a back up, there is a much higher chance of forgetting it if you never have to enter it compared to if you are entering it frequently.

Having said all that, I still think it is a nice option to have. In terms of plausible deniability - if you are using the "attach to secondary PIN" option, then there is a much higher chance that you are only using a single passphrase protected wallet than if you are using the "set temporary" option. If you use both, then you can give up both your main PIN and your secondary PIN, and an attacker is more likely to believe that you have no more hidden wallets behind other temporary passphrases.

This is not correct. If you double spend the unconfirmed parent transaction or pump its fee with RBF, then this means the parent transaction is being replaced with a brand new transaction. Doing so will invalidate the unconfirmed child transaction. Even if your new parent transaction sends the same amount of bitcoin to the same address(es) as used by the unconfirmed child transaction, your new parent transaction will have a different TXID from the one it is replacing (since something else will be different about the transaction - at a minimum, how much is being paid as a fee). Since transactions rely on the TXID of previous transactions to identify which inputs to use, by changing the TXID of your parent transaction, the inputs the child transaction uses will no longer exist and so the child transaction will be invalid. You would have to recreate your child transaction using the new outputs from your new parent transaction.

The only way to pump the fee of the parent without invalidating the child would be to use CPFP on a different output from the parent, which will speed it up without replacing it with a different transaction.

As mentioned above, any major centralized exchange such as Coinbase, Binance, Kraken, Gemini, Bitstamp, etc., are going to have a lot of security checks, very invasive KYC requirements, and delays sending and receiving USD thanks to the slowness of the fiat banking system.

If you don't want to go through all that, then your only other option is to trade peer to peer with another user, although this also won't necessarily be very quick the first time you set it up. You'll need to use a decentralized exchange such as Bisq, LocalCryptos, or Hodl Hodl, find an offer you like (or post your own if there are none you like), and follow the necessary steps of sending your BTC to escrow and waiting for the USD payment from the other party. You can choose what method you would like to receive your USD, but if you choose a standard wire transfer then you'll still be subject to the several day delays that these take.

Ahh yeah, I forgot about the SD slot on the Trezor T, which is what I assume you are referring to. Thanks for the correction. Still, Trezor recommend everyone use an additional passphrase as an extension to their seed phrase, which is the only way to be safe against this vulnerability if you are using a Trezor One.

Just as importantly, using multiple passphrased wallets is the only realistic way to have plausible deniability against a physical attack when using a hardware wallet.

It's difficult to know, but reading OP's post it sounds like he has sent bitcoin to the address of an old paper wallet which he has previously swept funds from in the past, and no longer has the private key to.

You cannot import a private key in to an Electrum wallet created from a seed phrase, be it an Electrum seed phrase or a BIP39 seed phrase. If you want to import private keys to Electrum, you have to create a new wallet which is only comprised of imported private keys.

Now is a very bad time. The mempool is backed up and fees are high, and your fees will be even higher since you are spending from a disabled 2FA wallet since it uses multi-sig. I would sit tight for the time being and keep an eye on the mempool for when it starts to empty out significantly, which will likely take a couple of weeks.

Alternatively, if you have to make a transaction now (as a payment to someone else, for example), then you could redirect any change from that transaction to an address in your new non-2FA wallet. Doing so would not incur any additional fee than if the change had just been returned to the old 2FA wallet. To do this in Electrum, you would need to click on Tools -> Pay to many, and then in the "Pay to" box you would enter your payment address followed by a comma and the amount to pay, and then in a new line you would enter an address from your new wallet followed by a comma and an exclamation point. The exclamation point in this case means "send all remaining funds". So your transaction might look like this:

5 sat/vbyte would actual put you around 110 vMB from the tip. And regardless of whether he was 70 vMB or 110 vMB from the tip, both have pretty much zero chance to confirm in the next 24 hours. Hashrate is down, average block time is much longer than 10 minutes, and the mempool is continuing to fill. I suspect a 5 sat/vbyte transaction will be dropped from the mempool after the default 14 days before it confirms.

I don't think that's good advice. The mempool can do a lot of things in two days. Recently it has gone from requiring 20 sats/vbyte to requiring 200 sats/vbyte, and the opposite is also true. If you transact two days in advance, you could end up with a stuck transaction dozens of vMB from the tip, and you could also paying a 10x higher fee than is needed. It's far better to either transact when you need it and pay an appropriate fee, or keep an eye on the mempool and transact when it is relatively empty, rather than just firing a transaction away and hoping for the best.

You can correct me if I'm wrong here, but I think you have this the wrong way round. As far as I am aware, there is no way to encrypt your seed phrase which is stored on your Trezor device with an additional passphrase. The seed phrase is only encrypted by the user's PIN. The passphrase that Trezor recommend using to mitigate against this attack in this article is indeed the seed extension passphrase:


In the event that an attacker is successful in this attack, they would still be able to extract your encrypted seed phrase and then brute force your PIN in a few minutes in order to decrypt it. However, they would not be able to steal your coins because your coins are not in that base wallet, but in a hidden wallet behind a (hopefully) strong passphrase.

Coinbase do not keep a huge amount of coins a single address anymore like some other exchanges do, so you will not be able to locate a single cold wallet address.

Take a look at this transaction: https://blockchair.com/bitcoin/transaction/a289ea76bcc396412e90d63b90eb462ea2adb326aa027d5a1bb8864c7c152012

The 9 output addresses of this transaction all belong to Coinbase and were part of their old cold storage system, each holding around 66,000 BTC at their peak. At multiple times over the past few years they have all been emptied, with the funds on them going down a chain of transactions and being split evenly across thousands of addresses in presumably dozens of different wallets, in denominations from 2 BTC to 100 BTC per address. This is Coinbase's cold storage system now, so it is impossible to find any one single cold wallet address, and it is impossible to know exactly how much bitcoin they have in their custody.

That is a bad list of accelerators.
Number 2 charges absolutely ridiculous prices, in the region of 50x higher than necessary if you just did a CPFP transaction yourself.
Number 3 requires you to import your seed phrase to their software, which is always high risk.
Number 4 is an outright scam.

The only one on there worth anything is ViaBTC's accelerator.

This also is not accurate. Many accelerators out there simply rebroadcast your transaction, which in many cases does nothing to speed up its confirmation and can actually be more harmful since it delays your transaction being dropped from the mempool so you can try again with a better fee.

I think much longer, probably.

We are now around 130 blocks behind where we would be if the hashrate has remained stable. This deficit has been increasing over the last 24-48 hours. Because of this, the length of this difficulty period will probably be closer to three weeks rather than two (we are currently 4 days in), and we will be stuck mining at a slower-than-average rate that entire time. The mempool didn't clear out at all over the weekend when it usually does, so I expect the it to fill up even more over the coming week.

Given that that transaction is still around 50 vMB from the tip of the mempool, and the mempool is showing no signs of emptying, I think OP will be waiting weeks for a confirmation (or his transaction will drop). He will have to make another CPFP if he needs it faster than this.