It should dump a message in the log every 100K attempts though.

This error is not related to your problem. It's just that the wallet contain a new type of data that the bitcointools is not aware of. (namely, the most recent block that this wallet was synchronized with)

Do you have a thread where you describe the scenario that led to hung transactions ?
edit: I assume this is the one. My advice would be to wait a bit for the import/export private keys feature to be formally released in an official version. Then you can dump your keys to a text file and import back the relevant ones to a fresh wallet.

Awesome! And thanks.
(And also D'Oh! but of course )

So if there is a single error and it's not in the checksum, we just test len(privkey)*58 candidates.
For 2 errors we would test (if I'm not mistaken…) [(len*(len-1))/2]*58, still under 100,000 candidates, nice.

He didn't mention that he had contacted them.

@cuddlefish: Could you please clarify if you contacted them prior to the full disclosure, and how long. Thanks!

Wow, a malware that disable other malwares to keep low profile. Brilliant  

Another approach would be a "node-id attack" where the attacker would somehow control your neighboring nodes in the P2P overlay.
This way the attacker can distinguish between transactions you created vs transactions you are merely routing.
This can be achieved by exploiting the server responsible for the mapping of nodes.

(No sure if such an attack is possible on Bitcoin, you can decide to bypass the irc channel and only connect to trusted nodes)

I have imported and redeemed successfully the following "vanity" privkey generated by casascius.
I Posted a related challenge for when the person makes a typo while writing the privkey down.

This challenge is related to import/export of private keys and wallet and creating "off the radar" addresses.
I don't know if it can be done. (I still have the correct private key of course)

Scenario:
- I used a tool or the client to generate a completely off the radar address.
- I wrote the private key on a piece of paper and stored it in a safe.
- I secured some of my savings to the corresponding address.
- We are now some years later and I want to import it back and spend my savings.

Unfortunately, it looks like I made a typo while writing down the private key ! This is all the information that I have left :

privkey: 5JjNVWPaRTPg1i4etqfPHFnsDZ1Js5qBYXFH9G4jC2Drb6kERsm
addr: 18j6vJ39JFtHtgwNninSk4L61VzRhXBmoc (bbe)
balance: 0.10 BTC

hints:
- The address is valid, the privkey has a typo, the typo is not in the checksum bytes.

I don't know if this can be done due to the double SHA256 used for integrity check. Maybe we should have correcting codes instead (A non working destination address due to a typo is not very critical, but a non working privkey is).

Idea:
Maybe we could have a validateprivkey rpc call like there is a validateaddress. This way I might have checked earlier and realized the backup wasn't valid.

Reference threads
- Private key and wallet export/import
- Bitcoin Off The Grid (shell script to generate privkeys)

The probability for two addresses to match is much higher than 1/(2^112) though. It's more complex than doing 2^160/2^48. Check the Birthday attack.
Also, TiagoTiago mentionned using current mining resources to generate addresses, so I guess it's fair to say that the 2^16 figure is underestimated, that would be more like… 2^16 per second. (But there is not 4 billion miners, yet)

While we are on probabilities, and I'm by no means an expert in these, someone mentioned in a previous page of this thread that to find the "1Kahlahan…" vanity address (8 fixed chars) would take roughly 1.28e14 attempts.
I think this is underestimated. (It seems to come from the intuitive 58^8).
My own computation gives me 2.99e+15, which is an order of magnitude higher. (I decode the base58 and do the maths on the hash160).

You have probably seen the topics on wallet encryption and brainstorming?

Split private keys
[PULL] Wallet Private Key Encryption
Coinsplit

PS: ECDSA is a signing only algorithm, you can't use it for encryption.

I just went to see the option today as well…
Currently I hide them on a per case basis with ad block.

It has been fixed, you should pull again.

On commence à y voir plus clair:
- Papion a été empoisonné.
- Souffrant d'amnésie, il ne sait plus vraiment qui il était avant.
- Certains souvenirs reviennent par bribes.
- Notemment une forte connexion avec Bitcoin.

Ma théorie:

Papion = Satoshi.

Expliquerait pourquoi Satoshi a disparu de la circulation depuis plusieurs mois. Ils devaient l'avoir kidnappé et drogué.
// Musique de The Bourne Identity

I admit I haven't tried, but I think this would not apply smoothly to what's currently in the git repo (which I think is what SgtSpike is using?). As mentioned, the sources have been reorganized.
GenerateNewKey() for example is now in the class CKeyStore, not global to main.h / rpc.cpp. This is where GenerateNewKey(std::string vanity) should be too.

I do have some kind of patch too but I haven't worked out the threading yet. So it just hangs until it finds a match, which is not very nice.
SgtSpike, I think you are under Windows, do you use TortoiseGit? It will make things easy when you want to create/apply patches.

Don't forget the scale tests, you might need it

IIRC, fee is the only known mechanism to protect against the "penny flooding" attack.

@OT, Didn't someone point that simply returning true has broader impact that just removing the fee?

I concur.
The new tab is maybe not really needed. A dropdown list on the send dialog should be enough to keep it simple and still usable.
What if I need several input addresses to complete the transaction ?

Va à la banque en disant que tu as égaré un billet de 10€, on verra s'ils t'en donnent un

Il n'y a pas de banque dans Bitcoin. Le système est complètement décentralisé, tu es ta propre banque si tu préfère. Ça évite par exemple que ton compte soit gelé ou fermé.
L'impossibilité du double transfert est intégrée dans la technologie, et non corrigé après coup. Toutes les transactions sont irréversibles.

La notion d'individu n'existe pas au niveau du système monétaire bitcoin. Tu contrôle un certain nombre d'adresses et tu peux dépenser ce qui a été envoyé vers ces adresses parce que tu possède les clés secrètes correspondantes.
Je te conseille d'aller voir le wiki ou de lire le papier de Satoshi Nakamoto.

Ah Ouf ! Parce que l'autre jour j'ai fais du travail au « black » et je me demandais s'il fallait que je déclare quelque chose. Mais comme je n'ai pas signé de contrat, c'est bon ! J'ai rien à craindre.