KNOW Reddit Mentions | ChartExchange

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I keep seeing people give up on old blockchain.info wallets thinking the password is gone forever. Usually is but sometimes it isn't. The password is fine — the **hash extraction is silently broken**, so even the *correct* password never verifies and people brute-force for months against garbage. Here's the whole process, every gotcha, in order. I've had an aes file for about 10 years now that I got from an old coworker who at the time told me 'if I can get into it I can have it'. Today I figured I'd make a write up about it
**None of this cracks a password from nothing.** It tests variations of what *you* remember. If you recall zero fragments and have no seed phrase, I hope you live for a very long time we're gonna be here for a while. —
---
## 0. Before anything: work on a copy
cp wallet.aes.json wallet_backup.aes.json
Never touch the original. A corrupted source file is the one way to actually lose access.
---
## 1. Know which version you have
| Looks like | Version | Extractor flag | hashcat mode |
|---|---|---|---|
| Raw base64 blob, no `{ }` | v1 | `--base64` | **12700** |
| JSON with `"pbkdf2_iterations"` | v2 / v3 / v4 | `--json` | **15200** |
2013 wallets are almost always **v1** (a plain base64 string). Peek at it:
```
head -c 40 wallet.aes.json
```
Letters/numbers with no braces = v1. Starts with `{"` and has `pbkdf2_iterations` = v2+.
---
## 2. THE #1 SILENT KILLER: a UTF-8 BOM
If you ever opened the file in Notepad, Windows may have saved it with a **byte-order mark** — 3 invisible bytes (`EF BB BF`) at the front. This corrupts extraction and guarantees no password will ever match. Check:
```
head -c 8 wallet.aes.json | xxd
```
Starts with `efbbbf`? You have a BOM. Strip it:
```
sed '1s/^\xef\xbb\xbf//' wallet.aes.json | tr -d '\r\n' > wallet_clean.aes.json
```
This single issue is behind a huge share of "correct password won't crack" posts. Check it first, every time.
---
## 3. Extract the hash — with the RIGHT tool
The hash prefix tells you which tool actually ran. Get this wrong and nothing downstream works:
| Tool | Prefix | For |
|---|---|---|
| `bitcoin2john` | `$bitcoin$` | Bitcoin **Core** wallet.dat — NOT this |
| `blockchain2john` | `$blockchain$` / `$blockchain$v2$` | blockchain.info aes.json — THIS |
Extract (v1):
```
python3 blockchain2john.py --base64 wallet_clean.aes.json
```
Extract (v2/v3/v4 — the `--json` flag is mandatory or it errors/misparses):
```
python3 blockchain2john.py --json wallet_clean.aes.json
```
`blockchain2john.py` ships with John the Ripper (jumbo). If yours is old and chokes on v4, grab the latest from the openwall/john repo.
---
## 4. Verify the extraction BEFORE you crack
- **Prefix:** must be `$blockchain$` (v1) or `$blockchain$v2$` (v2+). If you see `$bitcoin$`, you used the wrong tool.
- **Length math (v1):** hash is `$blockchain$<len>$<hex>`. `<len>` must be a clean multiple of 16 (AES block size). Odd or weird number = broken extraction (usually a leftover BOM).
- **Known false negatives:** some wallets whose decrypted JSON starts with `address_book` (instead of `guid`) get reported as "wrong password" even when correct. If you're *certain* of the password and it won't verify, this or a BOM is why — not your memory.
---
## 5. Prove the pipeline with a known-answer test
The step everyone skips. Make a throwaway wallet with a password you KNOW, extract it the same way, and crack that first. If the known password pops out, your tool + mode + format are all verified. Now you can trust a "not found" to mean "not in the wordlist" — not "my setup is broken."
---
## 6. Crack it
```
hashcat -m 12700 -a 0 wallet.hash wordlist.txt -r rules/best64.rule
```
- `-m 12700` for v1, `-m 15200` for v2/v3/v4.
- v1 is only 10 PBKDF2 rounds = fast, millions/sec on a mid GPU. v2+ uses many more iterations = much slower, so lean harder on a *targeted* wordlist.
- hashcat flags a hit when the decrypt comes out as clean printable ASCII (valid JSON).
**Wordlist beats brute force.** Seed it from memory — old passwords, pet/family names, handles, street numbers, the year (2012/2013), favored symbols — then let rules mangle it. Forgotten passwords fall to the owner's own habits. (Real example: The wallet I did today whose password was just `Name + birth year'. `best64` catches that instantly.)
Prefer a GUI/CPU path? **btcrecover** runs straight against the `aes.json` with a token list and handles all versions internally — slower but foolproof for format issues.
---
## 7. "I only have my Wallet ID, not the file"
blockchain.info serves the *encrypted* blob to anyone with the wallet identifier (GUID) — it's encrypted, so that's safe. btcrecover's `download-blockchain-wallet.py` pulls it down; then you crack it offline. This is the move most people miss when support says "we can't help you."
---
## 8. You cracked it — now get your coins
1. Decrypt offline (btcrecover, or blockchain's official decrypt tool) → you get the private key(s).
2. Import/**sweep** into Electrum (New wallet → import keys → sweep) → sends the balance to a fresh address you control. ~10 min.
3. **One private key = TWO legacy addresses** (compressed + uncompressed). Old wallets were inconsistent about which they showed — always check both.
---
## 9. Check the balance (permanent, all-time ledger)
```
https://blockstream.info/api/address/<ADDRESS>
```
---
## Common failure modes (and the real cause)
| Symptom | Actual cause | Fix |
|---|---|---|
| "Correct password won't crack" | BOM in the file | Strip `EF BB BF` (step 2) |
| Hash starts `$bitcoin$` | Wrong tool (bitcoin2john) | Use blockchain2john |
| v2+ won't extract / errors | Missing `--json` flag | Add `--json` |
| Hash `<len>` is odd/weird | Broken extraction (often BOM) | Re-clean, re-extract |
| Certain password still fails | `address_book`-prefixed wallet false negative | Use btcrecover, or newer tooling |
| "No hashes loaded" | Malformed/partial hash | Re-extract from a clean copy |
---
## TL;DR
Sometimes the password isn't the problem. Check for a BOM, extract with the right tool, verify the length is block-aligned, prove your pipeline on a known wallet, then crack with a memory-seeded wordlist. Diagnose the tooling and you'll solve it in an afternoon with a decent GPU.
*Happy to help. Don't send your backup files to weirdos.*