SD

Unlock_Pulse

ELI5: air gapped means the device never touches the internet at all. No WiFi, no Bluetooth, no cable, ever. So not your everyday phone. People use a cheap spare device or a hardware wallet. You sign transactions offline and only move the signed transaction across (QR code or SD card). The private keys never leave the offline device.

Playamonkey

You can get full residency in SD and never live there!

eld101

Was running on a pi and the SD card took a poop. I wrote down my seed on something but lost it.

Interesting-Gear-992

This is technically correct. But the Average Joe will never initiate a transaction on Linux, on the not very user-friendly BTC Core, move the transaction data on an SD card to another offline (more than one in case of multisig) Linux-based signing laptop, then move the signed transaction data back and broadcast it. So there will never be mass adoption. If this is the only truly safe solution out in the wild, then this will remain a playground for nerds.

equity_zuboshi

that is rare good advice on reddit, bravo. but you left out some unpopular parts: * always keep your hardware stateless - never leave your keys/seed sitting on a piece of hardware ready to sign. Seedsigner is stateless, so its a great suggestion. * that means you will have to type in your mnemonic every time your power up your signing device/computer. That means your mnemonic is your password. * dont use windows or macs or any closed source os for your online wallet or watch only wallet. If you do, even if your keys are safe across the airgap you can still be robbed. keep it simple with a basic linux for your watch only wallet / tx broadcasting / online shopping laptop. * dont use USB to transfer signature/address across the airgap. Also dont use a camera. keep it to SD cards. (dont use seedsigner camera) * dont leave your seed laying around on paper for others to find, memorize it like it is designed to be. No its not hard, most people just dont understand how mnemonics work. Its the easiest thing you will ever do, and the one and only way a human can safely hold entropy * Obviously, falling out from the above, extra-word and human chosen passwords/pass phrases are useless and should be avoided. Your menmonics words are your password, simple as.

apricotR

I'll stick with my SD40 but I'm in the same camp as you.

KeyBackRecovery

One thing I would do before attempting any more rooting or NAND work: stop treating this as a single-phone recovery. You mentioned that you went through multiple Android phones, that some of the later phones still show old transaction history, that you have at least one SD card of uncertain origin, and that you have screenshots showing the old balances/transactions. I'd inventory and preserve all of that first. For each old phone and SD card, record the exact model, Android version if known, whether it boots, whether Bitcoin Wallet is installed, and whether any Bitcoin-related files/backups are visible. Image removable SD cards before searching or modifying them. The screenshots and transaction history may also be useful for identifying addresses or transactions on-chain. That could help establish which wallet/device you're actually looking for before taking any invasive step on the Incredible. With the amount potentially involved, I would avoid repeated rooting experiments on the original device until you've exhausted the non-destructive evidence from the other phones, SD cards and transaction records. If you're still working on this, I'd be interested to know how many original phones/SD cards you still physically have and whether any of the later phones can still open the old transaction history.

significant_soldier

You don't need Sparrow, Nunchuk, or any third-party GUI coordinator to reconstruct or spend from a multisig setup. The Bitcoin protocol doesn't have a concept of "coordinators"—it only understands Script, Output Descriptors, and Partially Signed Bitcoin Transactions (PSBTs, BIP 174/370). Here is the exact technical blueprint for how recovery works without coordinator software: ### 1. What You Actually Need: The Output Descriptor The biggest pitfall in multisig is thinking that having your 2-of-3 seed phrases is enough. It isn't. Seeds derive individual keypairs, but they don't record: * The quorum threshold (e.g., 2-of-3 vs. 3-of-5). * The cosigner public keys and their sorting order (BIP 67 lexicographical sorting). * The specific derivation paths used (e.g., `m/48'/0'/0'/2'` for native SegWit). To make your multisig truly coordinator-independent, you must back up your **Output Descriptor** (standardized under BIP 380–388). It looks like this: `wsh(sortedmulti(2,[fingerprint/path]xpub1...,[fingerprint/path]xpub2...,[fingerprint/path]xpub3...))#checksum` With this string and your signing devices/seeds, your setup can be recovered in any software or directly from the command line indefinitely. ### 2. Recovery via Bitcoin Core (CLI / Headless) If every coordinator disappeared tomorrow, you could load and spend from the multisig using standard `bitcoin-cli`: 1. **Import the Descriptor:** Create a watch-only descriptor wallet in Bitcoin Core and import your descriptor string: `bitcoin-cli -named createwallet wallet_name="multisig_recovery" disable_private_keys=true blank=true` `bitcoin-cli -rpcwallet="multisig_recovery" importdescriptors '[{"desc": "<YOUR_DESCRIPTOR_STRING>", "timestamp": "now", "active": true}]'` 2. **Construct the Unsigned Transaction (PSBT):** `bitcoin-cli -rpcwallet="multisig_recovery" walletcreatefundedpsbt '[]' '[{"<DESTINATION_ADDRESS>": 0.5}]'` 3. **Sign with Signers / Hardware Devices:** You can pass the base64 PSBT directly to your hardware signers (via SD card or USB) or sign via the command line using **HWI** (Bitcoin Core's open-source Hardware Wallet Interface): `hwi -t <device_type> signtx <PSBT_BASE64>` 4. **Combine, Finalize, and Broadcast:** Once you have signatures from your threshold (e.g., 2 of 3): `bitcoin-cli combinepsbt '["<PSBT_WITH_SIG_1>", "<PSBT_WITH_SIG_2>"]'` `bitcoin-cli finalizepsbt "<COMBINED_PSBT>"` `bitcoin-cli sendrawtransaction "<FINAL_HEX>"` ### Best Practice for Your Backups Today In Sparrow, go to **Settings > Export** and export your **Output Descriptor** (plain text) along with the configuration file. Keep a physical copy of this descriptor alongside each of your seed backups. As long as you have that descriptor and the quorum of keys, your funds can always be recovered using pure open-source primitives.

Electrical_Chard3255

Yes, I do also have an option for 2 of 3, its just not written up yet, but its on the SD card, so any 2 of 3 will give you the seed, so when you go in to create the seed, and then the parts, you get asked do you want 2 of 2, or 2 of 3 option, with the explanation of the differences, the important thing is, no matter which part you have, then with the BIP39 sheet, unless you have 2 parts, your part is useless. I was initially reluctant to have a 2 of 3, if I gave two of my sons a part each, and I have the third part, if we fell out, they essentially have the seed, unless I changed it of course, but the option is there as the "recovery if one part is lost". I kind of made a point of saying for the duel parts, create 3 copies of each, you could create 20 copies, as long as they never meet, then the seed is safe. But the inheritance was a big part, as I mentioned, everything else relied on a company, a cost or some other insecure way, i think I have created a simple secure way for an heir to recreate the seed when the time comes, with or without the software, and its costs nothing other than the initial setup, and the pad and cypher can be kept on long term media, like a M-Disc, a steel plate (I have a 3D printed jig for the punch to go into, and of course a thumb drive, QR qode, dead mans switch, I could give you one of my halves, and its meaningless unless you get the other part

LNCrizzo

A lot more people would have gotten screwed if CC didn't make their product extra difficult to use. I went with a different HWW because I didn't want to deal with transferring transactions via micro-SD, but I had a CC in my cart on their website at one point. So that's the closest I came to getting rekt because I did end up using my device's seed generation for my seed, though I did also use a passphrase.

SuitApprehensive3240

So there's probably still a lot of jobs.I know not everybody wants to be an accountant , but it's a good job... And can probably get  an extension if you need it ...SD wish I was at the beach right now.My brother lives five miles from the beach , but he's north of you

TheGreatMuffin

I used to run a Raspberry node setup by (an older version of) Raspibolt: https://raspibolt.org/ It says "updated August 2026", so hopefully it's not outdated. You can skip the Lightning part and only use the parts that you are interested in. Another one would be Raspiblitz: https://docs.raspiblitz.org/ Very similar concept but a bit easier to setup, because AFAIK you just burn an SD image on your Raspi. On the other hand, the Raspibolt one teaches you how to verify signatures and so on, so that's just a trade off of how much tinkering you enjoy vs convenience. There are probably other guides as well, and otherwise yeah, an llm might offer a guide that covers the basics. Have fun :)

miner_guy_22

Look into Krux wallet. It is an opensource DIY project similar to Seedsigner, but has the option to save your seed in encrypted form, either on an SD card or encrypted QR. [https://selfcustody.github.io/krux/](https://selfcustody.github.io/krux/)

Main-Massive

They could have added a warning on the site, sell at a discount, have users accept the risk, and perhaps be nice and include an SD card with the new firmware. Even if they sold at a 50% discount I am sure they would be some profit to make. OP has a point on this being a possible degenerate buy

Icy_Giraffe_21

Comes with three secure element chips, supports dice rolls. Psbt with SD card and qr code. Can also go the lest popular way with the USB c cord also. Works with sparrow and other wallets

Icy_Giraffe_21

Awesome, you answered all my questions. Definitely going to look into the plus version with SD card. That's my flavor

PlanNo3321

The claim that “anyone can take out the SD card and read the secret off of it” isn’t accurate for how SeedSigner actually works. By design, SeedSigner only temporarily stores seeds in memory while the device is powered, and all memory is wiped the instant power is removed. Also, the SD card only ever contains the *software* (the SeedSigner program itself), never your seed. So pulling the card and reading it wouldn’t reveal a seed, there’s nothing there to find. There’s also no “air-gap mode” you have to switch on. The whole device is inherently air-gapped by design (no USB/WiFi/Bluetooth at all).

tenuousemphasis

There is the issue that a SeedSigner isn't as secure against physical access as a hardware wallet with a secure chip. Anyone can take out the SD card from your Raspberry Pi and read the secret off of it, unless you use air-gap mode which is a huge pain in the ass.

satsugene

They can both be true.  People try to use Tails Linux, for example, which is a really neat and useful platform, and hold their keys in persistent storage, and one bad update or USB thumb drive failure lose it. Same issue with RPi/SD card implementations. Worse if they try to VM it (dumped memory state attacks, vulnerable hosts). Folks rolling their own on stuff they barely understand and won’t keep up to date, or build using out of date YT walkthroughs instead of current official instructions, caries different but similar consequence risks. Then it becomes how do they backup the key. Too many are going to type it on their phone or PC or photograph it, or not back it up at all.

Personal-Time-9993

All you need is a raspberry pi and a case that snaps together. If you can get those and can image an SD card, you can do it yourself. You can buy as a kit also. The important part is learning how to verify signatures, so you know your software is authentic. That goes for any firmware/wallet.

yittirium

You technically could and would probably be fine, but given the technical ineptness of the coldcard team, I’d avoid it. IF YOU THINK YOU DO, get an intel thinkpad, a USB, an SD card with the read/write lock. download a live linux ISO from a pc, something super barebones and stable, or better yet even **Qubes OS**. flash it to the USB. Then reflash the bios chip directly by clipping to it and removing intel IME (a remote access “backdoor” in every intel chip) install the Qubes to the thinkpad, LUKS encryption with 6-7 word passphrase, download electrum/wallets of choice, then remove the wifi card from the laptop. Move signed transactions with the sd card in its own qube isolated from your wallet, then when putting it in another computer to broadcast transactions put the read lock on (little slider) to prevent transfer of malware, though Qubes would defend against that. If you’re looking for a new wallet, just get a trezor. It’s the most renound hardware wallet brand, no scandals besides some front end hacks like ledger. Nothing threatening your crypto. Old models like t1 and model t could technically be brute forced with physical access, but they were made before secure elements were a standard for these wallets. Hell, they were the FIRST hardware wallets so I wouldn’t hold it against them. You don’t need an “air gapped” wallet. No slander but if you’re asking this question you probably don’t understand how hardware wallets really work. The threat model where you’d need an airgapped wallet is one where you’d probably be verifying the source code of it yourself, like by line. Trezor keys are technically airgapped on the secure element. Theoretically some targeted malware on your pc could send scam transactions to your trezor if it’s connected and unlocked, but just don’t sign them on the device and you’re fine. You have to hold down for some time to sign anyways. Not a shill, I’ve owned many trezors and ledgers and have been in the crypto space for \~7 yrs. You don’t really need something airgapped.

10kpizza

There is no cloud, its just someone else's computer. You can make multiple copies of paper/metal put in difference places, same as the SD cards. Fire/theft can also destroy SD cards.

xiskghferx

It almost impossible, that fresh OS install on RPI would connect to any wifi or bluetooth by itself. After the calculation, i would format SD card, using dd and never use or connect this RPI to internet.

CrackerJackJack

This is a tough one because I don’t think you were actually hacked. The problem looks like it was probably self address verification. Your history is full of lookalike addresses. You sent to 0x9b9Ae2db…b44F62, and there’s also 0x9B9A3299…4F62 and 0x9b9A34b3…4F62 in your history. Same first four, same last four. Those got planted by counterfeit USDC contracts using Unicode lookalike characters (eg. ÚSDС, UṢDC, ՍꓢƊС) plus zero-value real-USDC transfers, so each one shows up looking like a legit past payment. You almost certainly copied one of the wrong ones, and the truncated display made it look right. There was no transferFrom, no drainer contract, no approval. You signed it yourself with your own key. Funds ended up at 0x88F8eCbA… on Aug 1. Your only real shot is if that’s an exchange deposit address. Worth reporting fast with the hashes, though it’s almost certainly already through a bridge or mixer. Sorry OP, that’s a really unfortunate situation. It’s sad but **strong reminder to everyone to always check the full address when sending, not the first and last four, and never copy from transaction history.**

YoshiGreenBag

No keeping on cloud is very smart because there is 2 factor authentication. You can also hide that file in bunch of other files; nobody will know what it is. Your idea is truly stupid. If there is fire or theft you will have lost your crypto. Paper burns and rots, metal is hard to hide and easy to find. SD cards are also good, that why i said make multiple copies.

MriLevi

For the pretty much every user an SD card is completely safe. In theory, SD card firmware _could_ be compromised, but I disagree with you, it does not happen. Its possible, it doesn't happen. And even if it was compromised, if you use an airgapped device to read it out, it'd never be possible for the bad actor to steal your data anyway.

jigajigga

No need to get defensive. My only intent was to say that an SD card \_can\_ absolutely be compromise with malware. SSD's too, of course. But sure, I made a mistake saying SSDs when I should have originally said SD. But SD and SSDs are both capable of being implanted. It's quite uncommon to hear about, but it does happen. That's all.

MriLevi

My original point still stands - SD cards are not gonna be compromised. And as it turns out in this case, it was not the culprit - badly written or even maliciously written software was. I don't know why you went into some overexplanation about SSDs - the terms are not and never really have been used interchangeably.

10kpizza

Keeping copies on the cloud is very very stupid. Yes they're protected by encryption but that depends on your encryption passphrase for which its difficult to make entropic enough. SD cards are pointless, failure-prone and unnecessary when you can write the seed words on a paper or metal backup and use the passphrase to encrypt. Separate clean laptop with read-only OS (ie live boot) only used for bitcoin is fine though. A raspberry pi works for this too. Seedsigner is a nice project that makes this easier.

MriLevi

we're not talking about SSDs, but about SD cards.

bongosformongos

USB sticks were, are and never will be a reliable long term storage. Be ready to see an empty or corrupted file when trying to restore in 10 years. Same goes for SD cards btw. Backups, backups, backups, and rewrite, rewrite, rewrite. Or just go physical and forget all that fuss.

omg_its_dan

I think as long as long as you do the dice rolls properly (ie use fair dice and do enough rolls) then the output can be trusted as random. I can’t speak specifically to the keystone though, I am still deciding. Air gapped means that the seed phrase never touches another device with a cable. With one of these wallets you need to load transactions on an SD card and sign it with the device, then move the signed transaction file back to your PC to broadcast the final transaction. It adds a step but isn’t too difficult. My thinking is with a multisig setup it’s ok to use one non air gapped device, because even if that was hacked somehow, you can’t move any funds with only one seed. This will mean that when I want to send, I’ll sign the transaction via the trezor connected to my computer, plus an air gapped signature on the keystone or cold >!card.!<

Mission-Ant-9258

If I'm understanding your question correctly: you were not affected, transfered your funds somewhere else, and you're now asking if you can delete the files in the SD card after the transactions were confirmed. Correct? If that's the case, then let's hope you can delete them because I did so too. Fingers crossed.

viper2097

Trezor and Ledger don't have SD card slots so it's not something they do. As far as security "generally speaking"; The fear that many people have is that a computer with a virus could be used to inject malware onto a hardware wallet or somehow be used to extract the keys from the secure element. Obviously there are absolutely no reported cases of a hacker being able to pull off anything CLOSE to this but people were still paranoid about it. Coldcard brought this feature out as a sales pitch to the people who were worried about such an attack. The cool thing about SD cards is that the good ones have a little "Lock" / "Unlock" switch on the side, When in the lock position, The SD card becomes "read only" The idea is that you could sign transactions on your Cold card's SD card with the tab set to "Unlock" and then pull it out, Switch it to "lock" (read only) and put it into a computer and broadcast the transaction, You could then remove the SD card from the computer and put it right back into your cold card and know with 100% certainty that nothing malicious was written to the SD card as it has a physical switch on it making it impossible.

DramaticWealth5985

You can't practically verify what a physically connected device actually sends through that connection. You can however verify signed transactions from SD or QR code on an offline computer first before transmitting to the network.

viper2097

That could be a really lengthy answer but I could maybe give you one example even though it may not answer your question. 1) Say I have three BTC and three kids and I'm planning my inheritance to make sure everyone gets 1 BTC, I could use the cold card to sign three different transactions on three different SD cards and give it to my estate lawyer for when I die. This is a very secure way to guarantee a transfer will be made at a future date without any middlemen or hackers changing my wishes. I'm not giving my private keys to anyone, Just three signed transactions that only sends a set amount of BTC (1) to a specific address (Little Joey's BTC address) All my estate lawyer can do with these files is broadcast the signed transactions, the address can't be changed and the amount can't be changed.

JanPB

Can't SD cards be infected too? Besides, if, say, Trezor does not have a physical path in its circuitry to output the keys, what difference does the air gap make? I thought the entire *point* of HW wallets was that you could connect it to a totally infected computer and still be fine because it's just physically impossible for the keys to leave the relevant microchip (which was precisely the Ledger debacle some time ago).

viper2097

The Ledger/Trezor is either cabled or wirelessly connected to a computer/phone that's connected to the internet when signing transactions. One of the selling points of the cold card is that you can sign a transaction on an SD card and then put that SD card into a computer to broadcast the transaction so that the cold card never actually touches a device that's connected to the internet. Like others have said, None of that really matters if the seed was created using 40 bits of entropy.

Old-Cardiologist-545

No, I asking if I can delete them… to make more space on my SD card. These are old transactions that are already confirmed. Is there any point in keeping them. Unsigned transactions that you no longer need, signed transactions and anything else that is taking up space that isn’t needed.

hk371

They could still add data from camera, NFC, SD card as input to seed generation.

Rtxenjoyer

If you are determined to have the most secure hardware wallet setup, here is a surface level guide. For maximum security, I would recommend SeedSigner and assembling it yourself. Buy the parts, such as the Raspberry Pi board, camera, and display, from reputable vendors. If you are really paranoid, buy each part from a different vendor. Do not buy a prebuilt SeedSigner, as that defeats the purpose of building it yourself with off-the-shelf parts. Nobody will know that you are using the parts for a Bitcoin wallet. The best board is the Raspberry Pi Zero 1.3 because it has no built-in Bluetooth or Wi-Fi, but it is harder to find in stock. If you buy the Raspberry Pi Zero W, there is a guide on GitHub showing how to physically remove the Wi-Fi and Bluetooth capabilities. When it is time to flash the SeedSigner OS onto the SD card, make sure you download the latest release from GitHub, along with the SHA-256 files, so you can verify it. You can also verify the SeedSigner PGP fingerprint from different sources, such as Keybase, to confirm that you have the authentic SeedSigner OS. Before creating your seed using the dice method, which I recommend, you can verify that the dice inputs are correct using the iancoleman website. This allows you to confirm that SeedSigner outputs the correct seed from the numbers you enter. When you have fully built the SeedSigner and are ready to create your seed. Use casino dice, preferably, or multiple dice. Roll them 99 times and write down the order on a piece of paper. Then enter the dice rolls into SeedSigner multiple times to make sure you get the same seed every time. You can then store the numbered sequence on paper instead of storing your seed words. For a bad actor, it would be much harder to recognize that it represents a seed phrase containing your Bitcoin. For maximum security, also add a complicated passphrase and store it separately from the numbered sequence. For additional security, you could set up multisig using wallets from other vendors as well, but I will not go into that.

blurred_rabbit

Sorry to hear this and props for stacking for 8 years man. I was never able to be that consistent with it even though I sat through several cycles learning that BTC goes back up. Life gets in the way so had to sell here and there. Coldcard airgapped w/ micro SD was my go to. There hasn’t been a single issue since I started using them back in 2021. It is unreal to me that there was a bug around one of the most important parts (initial seed generation). This is something you can’t just patch later on unfortunately. Thankfully for me I always did at least 100 manual dice rolls and a complex passphrase which I think saved me this time around. Only thing that would make you feel better is to consistently start stacking back in bitcoin or some other investment and as time goes on it all becomes a blur and you will feel better.

Specialist_Trust4945

I wouldn't use an SD card for TX signing because it kind of defeats the purpose of keeping the device offline, but other than that super solid setup.

SpareEconomy1849

Yeah kinda dumb that they have 6 different colors and they are all ugly. I think it fits with the functionality though, you gotta export a file to the SD card, sign, move back to your PC, then upload etc all with some 3rd party open source app. I prefer it, but it's definitely not appealing to the average person

jwhendy

Thanks for the detailed reply! Glad to have a nuanced dialog (rare these days) :) > Of course many novice users are just going to follow the default setup procedure In hindsight, just wow, for how security-forward they are, it kind of blows my mind they have the beginner approach at all. Like why not just mandate dice rolls just cause? Don't even have beginner/medium/paranoid guides, just paranoid. > As I added in another comment I wouldn't use a product developed by a company with less than 10 employees and a shoe string budget. I did not know these facts and those were some of the most eye opening and best points I think you made. Just comparing employees, capital, investments, reviews. I think the critical breakdown was absolutely in the diligence/review process. >Further, they are judgement proof. If the software fails and/or gets hacked a company with less than $1mm in assets will immediately go bankrupt with no possibility of recovery. Yeah, in some other thread someone was talking about how folks will get money back and mentioning insurance. I'm like... this is going to be like a 1929 bank run (ok, not quite). There's just not going to be enough to go around. Tragic. > Your private keys never leave the hardware. Thanks for the rundown on this. I have little experience across the various wallets and how they work. So this sounds better than my initial read, just with *some* degree of trust that this is what actually happens. Like compare: - in theory, if everything is working properly, the Coldcard uses the hardware based TRNG... unless someone messed up the implementation - in theory, if everything is working properly, there's no way a USB connection could be used to access the private key If we rewound the clock a week, I actually don't know which of these at face value one should/could be more paranoid about? The whole thing opens up just how much we rely on humans (and even AI) to get all of this right. Don't accidentally commit with some `debug=True` flag on, for example. Who the hell knows all the possible ways that what *should* happen might not *actually* happen. > I would comment that this adds some complexity for the novice users when you start adding qr codes, sd cards... Totally fair. I have been using linux for like 20yrs and love the option to do some of these things vs. the impossibility of them, even if others connect up with USB. Copying a partially signed transaction to SD and back is all good, but there is fully a reality of how to reduce all of the cryptography details into something usable. Imagine we had to have some mental model of wind resistance, friction, air/fuel mixtures and whatever just to drive a car! Hey, dang, you have no idea how much I love a sane discussion, and found myself realizing how rare it is. I appreciate the interaction :)

Ok-Toe9937

That's rough, I'd probably try reflashing the firmware from a fresh SD card if you haven't already.

damnuchucknorris

Only coldcard, looking at everything it's probably some malware or something that they injected and just waited until their victim list got big enough. The vulnerability was probably on the SD card.

bastian74

Google says most SD cards will lose data in 1 to 10 years, depending on many factors

votegoat

Did you use the same SD card to migrate the seeed/private key, to then transfer the watch wallet file/ signed messages? or did you use two seperate sd cards? The SD card with the Wallet Private Key on it would still have had the private key on it even if you deleted it, unless you did a multi pass over write of the card.

bastian74

Doesn't an SD card have limited storage life?

MicroneedlingAlone2

"I used the same SD Card from 2021 though to export the wallet file from the newly restored coldcard. Import that file into Sparrow (needed to update Sparrow at this point)," when you say "export the wallet file" do you mean the entire wallet? Not just a watching copy, but a legit wallet with spend capability? AKA the private key was on that SD card at some point, and then got plugged into another device with Sparrow on it (phone, pc, something connected to the internet?)

Generationhodl

especially the part with sparrow is what makes me wonder. Right now there is a malicious sparrow app in the apple app store that seems not to be taken down regardless. I wonder if OP might have downloaded a bad / malicious version of sparrow, and as soon as the put the SD card into the computer or whereever sparrow did run - the Data on the SD Card got sent to the attacker. I mean there was the Backup on the SD Card, the seedphrase if I'm not wrong? so basically you put your seed into an computer or device to read the SD Card and put that file into sparrow. The counter-argument would be that there seems to be other people affected too, with coldcards... I really wonder what the big problem is.. or maybe that "fake" sparrow app was just used over a very long time until the attacker decided they have enough seedphrases now to rug them all.

joefunk76

At a high level, and someone feel free to correct me if I’m wrong about any of this, OP typed his original seed phrase into his new Coldcard while the SD card was plugged in, and then inserted his SD card into an Internet-connected PC. Based on everything I’ve read, my best guess is that the hacker somehow managed to remotely install (or trick OP into installing) malware expressly designed to record any seed phrase typed into a Coldcard, and then transmit that seed phrase back to that hacker the next time the malware on the SD card detects an Internet connection. When and how was the malware installed? That is probably extremely difficult to figure out, especially since OP has had the same SD card for 5 years. TL;DR: Hacker remotely installed malware on the SD card designed to record manually input seed phrase and then transmit back to him upon next detection of Internet connection. Call me crazy but this incident is making me question the security of devices that use independent physical media for data transmission as opposed to the device itself.

artilekt

It looks like this is a wide-scale attack though, something that would not be isolated to his SD card.

ConsequenceFew6931

OP I ran your timeline through Opus 5. Here is what it had to say: My bet is the SD card, and specifically that it carried more than he thinks it did. The reasoning that moves me most is timing. That wallet held real money continuously since March 2025 — 0.65 BTC sitting there untouched for ten months, with more added in November and December. An attacker holding those keys before January 2026 would almost certainly have swept it then. The only thing that changed in the wallet’s state was the restore. So whatever happened, it happened in that January 2026 sequence. Inside that sequence, the seed existed in four places: the paper, his fingers on the mk4, the mk4’s secure element, and the SD card. The first three are hard to attack remotely. The SD card is the only one that went into a networked computer — a computer he was, at that same moment, downloading wallet software onto. He believes he exported an xpub-only file. But that card had been sitting in the baggie with the paper seed since 2021, and SD cards don’t securely delete: anything written to it during the original 2021 setup and later removed is usually still recoverable. An infostealer or a trojanized Sparrow build doesn’t politely read only the file you clicked — it images the volume. Rough weighting of how I’d bet: **• \~45%** — compromised host (fake/unverified Sparrow update, or a pre-existing stealer on that machine) harvesting seed material off the 2021 SD card **• \~20%** — something he genuinely doesn’t remember or hasn’t mentioned; these accounts are almost always incomplete, and the real cause often surfaces three days later in the comments **• \~15%** — tampered mk4 (he never says where he bought them, unlike the mk3s which he sourced direct from Coinkite) **• \~15%** — physical compromise of the paper, timed coincidentally **• \~5%** — everything else The six-month delay is consistent with all of these, incidentally. Harvested keys typically go into a batch, get sold, and get swept whenever someone works through the queue — the lag is normal, not evidence against.

NiagaraBTC

You're certain you exported a wallet file via SD card and not somehow the private key itself? How certain are you that you were using a legitimate version of Sparrow?

cgimusic

Reminds me of those janky SD cards that had built-in Wi-Fi and would share your photos as you took them.

PassionGlobal

But a full.fat SD card has room for things other than storage...

so7ow

Yeah something doesn't add up for sure. He says he's going to drop some details later, so I guess we'll see. So far the only hint is something about an SD card that he hasn't really clarified.

Generationhodl

"Never hooked it up into a computer. Just the SD card." So you put the SD Card with the Coldcard-Backup (basically your seedphrase) into your computer?

Generationhodl

"Never entered seed into a computer. Just the Cold Card itself. No photo of seeds, just the watch-only QR. SD card imports the wallet into Sparrow." So did you use your SD-Card Backup from Cold-Wallet on your PC to import your 2021 Coldcard-Wallet into Sparrow? Does it have to do something with the fake-sparrow app from the apple store? [https://x.com/craigraw/status/1743573811230863813](https://x.com/craigraw/status/1743573811230863813) Could it be that you downloaded a compromised Version of Sparrow from some scammy site? Other people got scammed out of their bitcoin because of a fake-sparrow App / Software.

MriLevi

An SD card cannot be compromised, it has no connectivity on its own whatsoever. The data on it could only have been accessed if it was punt into a device.

memberwap

What did you do with the SD card? Did you backup your wallet into it and then put it in some laptop/PC? Otherwise I can't see how it was compromised.

s1ammage

This is my understanding… unless the SD card is compromised.

s1ammage

Never entered seed into a computer. Just the Cold Card itself. No photo of seeds, just the watch-only QR. SD card imports the wallet into Sparrow.

moviemaker2

You technically can but you don't want to take this route as a newbie. It's 100% easier, safer and just as economical to get a dedicated device. Essentially anything but a Ledger. I recommend a coldcard MK5, but other options like Jade, bitbox and others would be just fine. The simplified process is that you have a wallet on your phone or PC that doesn't contain the private keys. You initiate a transaction in that wallet, filling in amount, address, etc. and the hardware wallet authorizes the transaction. (either by being connected via usb, or if you want to go full airgapped mode like with the coldcard Q, you copy the transaction from the computer to the Q via SD card, sign the transaction, copy it back to the computer, and broadcast it.)

Search327

I started out with a self built Raspberry pi and MyNode but I had to keep formatting the SD card. I move to a used pre-built Start9 server and haven't had an issue since.

disruptioncoin

Bro one time I bought one of those hollow trick nickels off ebay and hid an SD card with information important to my business on it (it was my Tails boot drive). I chilled out for a year then decided to get back into business again, but couldn't for the life of me figure out where that nickel went.... I probably mixed it in with other change and bought a gas station coffee with it or something.

yesdaddy_____

Because I need to find the "protected" file in my internal or SD card storage. Which i can't access without SU

Different-Result-859

Yeah, got it. The card reader you need is one you can insert the SD card into it, and you can plug it into the USB slot of the computer. The SD card is usually more straightforward compared to accessing the Android. 3. Should be fine if write protection is enabled. 4. This is just software you can download with a Google search. It is actually easy. If you run into issues you can ask here. You can buy a $20 Claude Pro subscription to double check things since trusting somebody may not be always safe. 5. This is only if the data is corrupted and you can't read the SD card files.

yesdaddy_____

I haven't tried to read the SD card as of yet. I do have an SD card adapter (Larger card that the SD goes into) Neither do I know how to properly do steps 3-5 as you listed. I'm not a computer wizard. I don't know all the SDK & Platform tools correctly. I don't wanna accidentally delete or overwrite data

Different-Result-859

I just read that you are not even sure if it is the original SD card... But no harm trying. This is easiest to check IMO Let me just confirm the facts: 1. Do you know which parts of the HTC phone is dead? The screen? Battery? 2. Do you recall if the Bitcoin Wallet app that comes with this wallet is there even if the phone is dead or uninstalled? If it is installed, recovery is much easier. If it is uninstalled, it is very much harder. 3. You have checked your emails. Some versions of the Schlidbach wallet send you the backup by email. If you have not checked the emails that was in use in 2012, that can be the missing piece you need to unlock the wallet.

yesdaddy_____

Yeah, I read about basically every rooting method will wipe my data. It's been so long, I can't remember why the app isn't there anymore. But when I look through my other android devices. It shows all the transactions I've made. Like 900, 460, 760, 140 BTC etc. I'm thinking, maybe when switching phones in the past. (I don't recall the process) it would move the apps over to the newer phone. Unlike nowadays we have smart switch that basically moves everything to your new device. I'm almost positive it was running 2.3.4 I could try and check the SD for a back up file but it's been so long I'm not entirely sure that's the original SD card. Or if I even had an SD card in the phone in question to begin with.

Different-Result-859

No, that's risky. Buy an external USB SD card reader. That's safer.

eckstuhc

So a couple of things here.... Android 2.3.4 was the version that patched most of the known exploits (unrevoked 3, gingerbreak, etc.) If you are actually running that version, you are likely out of luck getting root. If you downgrade to Froyo it'll wipe your data, if you use the HTC bootloader-unlock, it'll wipe your data. I think "zergRush" works on some 2.3.4, but it's a long shot and not very likely. More importantly, was the app truly uninstalled or do you just not see it? (Settings > Applications > Manage Applications > "Bitcoin Wallet") If it's listed, the data is still there, but if the app was truly uninstalled, the wallet data is probably already gone. Uninstalling the app removes its private data directory, keys along with it. Your only recourse would be forensic recovery (NAND specialists). So... confirm if you are running 2.3.4 and if the app was truly deleted. Also, you said it has an SD card. Worth looking on that for a backup file if you haven't already.

Different-Result-859

You are using an external card reader to read the SD card with a computer, right? Are you saying that the computer is not detecting the SD card or not able to read the SD card? Have you done these too, to make sure the data is kept intact since even the act of connecting may make the computer do minor invisible edits? 1. Enable write-protection 2. Use external USB reader instead of built in laptop slots 3. Don't format or edit anything 4. Use OSForensics ImageMounter to create a raw sector-by-sector image file of the SD card 5. Scan the image, not the card if you can't find the file with data recovery software I think you are talking about accessing the internal data of the phone?

yesdaddy_____

I could try to use a card reader adapter (the one that fits an SD card into a larger card) on my laptop, would that suffice? I had a SD card port on my other PC but the power supply shot a fire ball into the sky. (The power supply blew up)

Different-Result-859

No doubt it is there in the internal storage. But it could be there in the SD card too, if you ever clicked backup wallet in the app. Since phone is dead, I think it is faster to check the SD card especially if you have a reader to plug it into PC

Different-Result-859

By checking. I have made some edits if you are checking SD card. Checking the device itself is harder.

yesdaddy_____

I've read that so many times on multiple forums. How do I know if its on the SD card or the phones internal storage?

Different-Result-859

Pretty sure I can help you. Read the SD card on your PC. Put it in a card reader and look for a file named like bitcoin-wallet-backup-2012-… (no extension), in the Download folder or the card's root. Once you have that, you can recover the wallet easily

TaxAdministrative447

I would grab a couple of the same HTC phones from eBay and use them as guinea pigs. Clone the SD card first and work from copies only. Then mess around with rooting/imaging on the donor phones until you have a process you're comfortable with before touching the original.

yesdaddy_____

Thanks for the advice. Yeah, alot of DM'S alredy. Anyway, The device in question is an: Android Incredible model number: ADR6300VW I belive the android version is 2.3.4 (the device is dead, I need to charge it to give further info. *side note: google stopped supporting this OS awhile ago. Which makes this harder to recover. The Schlidbach app is not on the phone. But i believe once I access super user I can access the protected files. (My other apps, wallpaper etc are still there, so no. It hasn't been factory reset or anything. It does have an SD card. To my knowledge and as far as I can recall, there was no PIN, password or anything about a backup. It would just prompt " The amount in your wallet is quite high for carrying in your pocket. Please move some to a safer place" As far as I've researched the phone NEEDS to be rooted to gain access to the protected files. But as you said, rooting the phone like whiching the OS the clock work recovery mod may or in most cases WILL delete all data.

eckstuhc

First, I highly recommend you refrain from any conversation via private messages or DMs. Keep things public, that way (hopefully) someone can call out if you are being scammed. Second, lets clarify: the funds do not "live" in the phone the way you think they do. That wallet in 2010-era was pre-HD, so you are correct there is no seed phrase, but the funds "live" as individual private keys. All funds are "on" the blockchain, your keys just enable you to sign for the corresponding public address (access the BTC). The good news - individual private keys are the easiest to import, those keys can be swept directly into Electrum without any other tooling. And you are also correct in that rooting does have the potential to factory reset your phone. Most rooting paths with /data which is where your keys exist. "Unrevoked" root uses an exploit in HTC-based devices that don't touch the data partition, but from what I know this is only HTC devices and pretty sketchy. I wouldn't go this route unless necessary. So ... questions: 1. What device make and model do you have? And how many? 2. Do you know what version of Android is running? (guessing 2.x given 2010-era) 3. Do they have SD cards or integrated storage? 4. Why can't you access the application itself? (phone doesnt boot, locked, app doesn't open, etc.) The truth: Depending on your make/model, I could help pintpoint a potential exploit-based, non-wiping root method, but it's a long shot. If you have access to the storage (SD card) you need to look for a file beginning with 'bitcoin-wallet-backup'. Historically these are saved to SD cards' /Download folder. Unfortunately, this is a manual backup that would've been completed prior, and prompts for a backup password when set (another hurdle if you do have one). Answer the above questions and I'll let you know what else can be done.

Either-State1365

I would also recommend learning to sign with microsd card/SD card, and learn to run your own node. If you don't run your own node, use multiple wallets and connect to different remote nodes to verify transactions.

bjman22

Interesting idea. I can think of one very useful function for such a feature. Say you want to be able to use the Q to type notes--eg. the combination to a safe where you have the SD card with the backup of your seed words stored or you even want to write in your note your passphrase for the seed phrase. Then you can export this note encrypted to a different SD card than the one where you stored your backup seed phrase. Now you have 2 SD cards which can be stored in different locations. If any emergency happens you can buy a new Coldcard and first put in the SD with the encrypted notes and read what your passphrase was and also the combination to a safe where you have your SD card with the seed phrase backup stored so you can open that. Then you put in your SD with the seed backup and your passphrase and you are back in business.

Fiach_Dubh

maybe i need to play with this more, but: iirc you have an encrypted note option ON device. you can also export notes I think, but i don't think they're encrypted while on the SD card? idea is to export notes from the device to the SD encrypted, so they can be reimported into the device to be decrypted. you now have a secure offline encryption decryption device sd card setup / analog protocol ?

r_a_d_

1. Because the hard part is properly handling your seed phrase, as I mentioned. 2. You still trust the device. You Always communicate via the qr code and SD card or whatever, otherwise you could never get the transaction information from the client, nor could you get the signed transaction to the block chain. So I would call them, different. Not better. The better approach would be to use both a cold card and a ledger with multisig. This way if either manufacturer tries some shit, you’re still protected.

mqfr98j4

Old phone, on the SD card, which has been gone for a good number of years

Far_Geologist_8049

Been using hardware wallets for a few years now and this is actually tough choice. Both are solid for long term storage but they have different philosophies. The Coldcard is more hardcore bitcoin-only approach - no USB connection to computer, everything through SD cards and QR codes. It's super secure but honestly bit more tedious for occasional transactions. You'll be dealing with PSBTs and need to get comfortable with that workflow. OneKey Classic feels more straightforward for someone who doesn't transact daily but still wants decent user experience when they do. The interface is cleaner and connecting to desktop software is less friction. Security is still very good, just not as paranoid-level as Coldcard. Since you mentioned ease of transactions is important and you're not daily user, I'd probably lean toward OneKey. The extra security layers on Coldcard are great if you're storing serious amounts, but for most people the convenience trade-off isn't worth it. Either way you're getting proper cold storage though.

WeGottaTalkAboutYT

https://docs.house.gov/meetings/JU/JU08/20250227/117951/HHRG-119-JU08-20250227-SD006-U6.pdf

Icy_Giraffe_21

It most definitely is air gaped. It never connects to your phone via Bluetooth or wifi, and you and utilize the micro SD card only to be even more secure

Street-Technology-93

Hawking a book using MIT SD

ChrisBattle2000

Also, it is amazing that he reaches such a doomster conclusion on BTC. His field is System Dynamics, a field which I have studied and worked in for over 20 years. Saylor makes amazing economic arguments using SD concepts and is responsible for a lot of the finance sector's pivot to BTC, so how come Keen can not see the value proposition? That is what I find inexplicable

ZedZeroth

They just mean store the seedphrase as a text file on the SD card and then encrypt it.

andzno1

>Imagine hauling metal plates through an airport if you can just encrypt a micro SDcard the size of a fingernail. 😂 How do you even engrave a seed phrase on a micro SD card?

rs1971

I don't know how long you've been in BTC, but the first hardware wallet wasn't even released until 2014. Early BTC forums / message boards were basically inundated with 'Help, my computer crashed and lost my keys!' or 'Help, I copied my keys to a SD card but I've lost it', etc, etc, etc. No one cared enough to take proper precautions (and it wasn't even clear how to do proper precautions safely) when the stuff was worth $4 a coin.

AcostaJA

Most hardware wallet work with desktop clients, some hardware wallet support PBST signing on SD cards which only need a desktop or mobile client while generating the transaction or broadcasting it (actually a fully signed psbt maybe broadcast by cut n paste at some block explorer/miner pools). A Bitcoin transaction needs to be broadcast, otherwise will never be mined (like having a signed check and never showing it at your bank)

NOLAgambit

I never said that he scripts part of his videos for entertainment therefore he’s going to set up a ponzi scheme. I straight up am saying he has committed fraud and therefore should never own a bank. Charles Ponzi is similar in that sense, but Charles Ponzi was GENUINELY A BETTER PERSON than Jimmy Donaldson, AKA MrBeast. Want me to make it easier for you? Here ya go: Charles Ponzi: Kind as fuck, but also didn’t understand finance as much as he understood how to commit fraud through leverage. WILLING TO ADMIT HE IS A GARBAGE PERSON. After all his bullshit, people were still willing to give him money to invest and ultimately screw them over. MrBeast: Sexual harassment, gambling fraud, rigged lotteries, rigged games, FAR TOO SOCIOPATHIC TO ADMIT WRONGDOINGS EVER. MrBeast is a worse and more modern Charles Ponzi. I think they’re both a great litmus test for finding out what idiots will trust a person blindly without verifying if they’re actually full of shit. Now if you’ll excuse me, I have to go back to Rockport to grab the last load of free golf carts to sell for a quick buck. There’s too many golf cart companies and it’s stupid easy money to transport them to South Dakota to sell at 5k apiece, there’s already a ton of buyers out there too, but I don’t have the equipment to travel there by next month, so I’m gonna sell them for pennies on the dollar. If anyone wants to DM me, I’ll sell you my golf carts for $300 apiece. I picked up about 200 carts for free for myself because I’m just charming and lucky and I work hard and wanted to start a golf cart business to match my other tour business. If you want some, you can DM me and I’ll send you the invoice. Even though I can’t transport to SD, I can TOTALLY transport to you anywhere in the country. And if you can trust MrBeast, you can also trust me. :) Anyway, back to sellin’ carts.

almbfsek

it's crazy people are using SD cards for important data. literally the least reliable storage media.