A server down time and a man-in-the-middle attack are additional risks, that's right.

This is really interesting:
Beware: in contrast to their online wallet where decryption takes place on your client side, when you use the API then you send your decryption password (in plaintext... okay it's a secure SSL connection but anyways...) and decryption takes place on their server.

I didn't know that. Thanks for sharing this information.

I think Armory will be the best choice.  What system do you use on Satoshi-Karoshi for instantly withdrawal?

There is a easy solution for you. Just post your service on a page like this: Bitkama.com
The page has an escrow and a ranking for every service. It's the easiest way to build trust.

I think he talk about the blockchain.info... because he write:
- i sent some btc from blockchain
- blockchain wallet
- blockchain wallet is stuck on
Have you used the shared transaction option?
Can you please send the "transaction hash" or the "send|receive address"?

Blockchain don't store the private key:
Is it secure? Will another mybitcoin.com situation occur again?
Yes, it is, and no, we are protected from such situations as all of your private keys are encrypted with your password before leaving your computer. We do not hold a copy of your password, and thus are unable to view or spend your Bitcoins. You retain full control of your private keys, so your wallets can never be seized or blocked and can be imported into any desktop Bitcoin client.
Source: https://blockchain.info/wallet/wallet-faq

I really like the solution from Armory! I can use a hot wallet without the risk of a hot wallet. The only problem is, I have to sign my transactions manually. That means no instantly withdrawals, right?
So lets say I manually sign the withdrawals from my service every hour. Then I still have a withdrawal down time of 7 hours each day, in which I sleep.

But everything else on this solution is absolutely perfect. Thank you for sharing this zaseb.

Thank you dominicus for this great guide. If you travel a lot, it's much easier to use a USB instant of a additional netbook

Hi zaseb,

thank you for the hot cold wallet description. This part is interesting: "The transactions are signed on this machine, the signed transaction is then moved to an internet connected machine where it is then broadcast to the network."
So I connect the cold wallet never ever to the internet, even if I make a transaction. That's fantastic!

"If your machine is compromised oauth or 2FA won't protect you so it provides no extra security."
Ok, that's a good argument. But if I have no security extras, why should I not use Blockchain.info?
They don't store my key and I can use features like, shared , sms, email ... transactions.
As you say, if I get compromised the hot wallet will be emptied, no matter what API I use.

I will have a look at the Amory Client. Do you have a set-up guide for a hot wallet?

Thanks
DaDeus

Hi,

I'm trying to better understand the Hot-Cold Wallet System  because I think it's very important to have a clear understanding of this topic.
There is no week without a new hack about an exchanger, service, game site ... where all bitcoins are stolen from the hot wallet.

I have made a lot of research about the hot wallet topic and found much informations, I want to share with the community.
But there are still questions I can't answer, maybe some user in the forum will help me.

The Hot-Cold Wallet System:

Source: https://bitcoinsecurityproject.org/SecureApplicationArchitecture/


The hot wallet
The hot wallet is what your service will use to receive and send bitcoins immediately. If you are sending bitcoins to a user for a withdraw, it comes from the hot wallet on the server. A good hot wallet only keeps a small portion of bitcoins available. An amount that allows your service to run for a week or even a day without running out. Say your hot wallet was 5%-10% of your total funds, you'd daily or weekly add bitcoins or take bitcoins. If there are no bitcoins on the hot wallet, your service should come to a grinding halt. You cannot automate the filling of the hot wallet from the cold wallet, this is dangerous and is exploitable.
The benefit of this smaller balance on the server is that you cannot get robbed of all your funds suddenly.

The cold wallet
The cold wallet should not be in any way connected to the internet. It'd be best if only you had access to it. 90% of your funds should be kept here. The idea is that the attacker cannot access 90% of your funds electronically or automatically. You should manually be moving coins from the cold wallet to the hot wallet by yourself.
Source: http://bitcoin.stackexchange.com/questions/21998/how-would-you-store-a-bitcoin-wallet-for-a-small-bitcoin-exchange


Now we know how a Hot-Cold Wallet System theoretically works.
The next step is to decide how to set-up such a system. I have found three different ways to build a hot wallet.

1. Bitcoind client
Compile the bitcoind client for your server and use a encrypted wallet direct from your server (or separated wallet server).

2. Coinbase api: https://coinbase.com/docs/api/overview
You can choose different authentication methods: API Key, API Key + Secret or OAuth2 (https://coinbase.com/docs/api/authentication)
After that you can choose the permissions like send, request ... (https://coinbase.com/docs/api/permissions)

3. The Blockchain api: https://blockchain.info/api
If I understand it right, you can choose between API Key and API Key + Secret (https://blockchain.info/api/blockchain_wallet_api)

In my opinion the safest way is Coinbase OAuth2 + permissions. Am I right?
Are there other ways to set-up a hot wallet?

It would be great if someone who know the topic can help me to share the best way to set up a Hot-Cold Wallet System with the community.
It's in our all interest!

Thanks
DaDeus

Yes. You can use this site: bitkama.com
Just open a job and choose the "Instant Delivery File" option.
Now you can send the link to people...

Hi,
I am developing a new service for Bitcoin. So far everything looks good.
But there is a problem that gives me a headache.
It's about storing bitcoins on the server.
If I look at other services such as localbitcoin or mining-pools it looks easy how they manage the accounts with all the bitcoins.
After I've research for it, I am unfortunately found no safe solution.
Is there a service who manage wallets securely and multiple addresses for them? Or do the most it on themselves?

I need for every account one wallet. Every time someone want to transfer some bitcoin to the wallet, a new address must be generate for the transaction. The transaction must be verify by the blockchain and after the verification the coin must be store in the wallet. I have no problem with outsourcing the wallets/payment service if there is a very secure! service with such an api.

It would be great if someone with experience can help me with some tips and advices where to start with this issue.

Thanks & Regards
DaDeus

@eiswuerfel

Steht das Angebot noch?

Grüße
Deus

Erledigt.

Artikel Standort ist München, gerne auch per Abholung

Habe hier noch Lüfter, Steuermodule, Kabel ec. aus meiner Minerzeit, kann bestimmt jemand brauchen, einfach einen Preisvorschlag machen:






Grüße
Deus

Hallo g83,

ich verkaufe gerade meine Mining Hardware, vielleicht ist ja was für dich dabei:
https://bitcointalk.org/index.php?topic=167397.0

Grüße
Deus

Hallo eiswuerfel,

ich verkaufe gerade meine Hardware, vielleicht ist ja was für dich dabei:
https://bitcointalk.org/index.php?topic=167397.0

Grüße
Deus

Hallo,

Verkaufe gerade meine Miner Hardware:

Energieeffizienter Basis Miner:
http://www.ebay.de/itm/130882848092?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

GPUs:
2x Sapphire AMD Radeon HD 5850 Xtreme:
http://www.ebay.de/itm/130882783370?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649
http://www.ebay.de/itm/130882782886?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

1x Sapphire AMD Radeon HD 6950:
http://www.ebay.de/itm/130882791107?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

CPU:
Intel Core i5 2500K:
http://www.ebay.de/itm/130882808273?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

Mainboard:
GigaByte GA-Z68AP-D3 + 8GB RAM:
http://www.ebay.de/itm/130882832937?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

Netzteile:
Super Flower Golden Green Pro 450W:
http://www.ebay.de/itm/130882841619?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

OCZ 600MXSP ModXStream Pro Netzteil 600 W:
http://www.ebay.de/itm/130882820520?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

Festplatten:
3x 80GB 1x 500GB:
http://www.ebay.de/itm/130882813174?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

Monitoring:
Netbook Acer Aspire One D250:
http://www.ebay.de/itm/130882772916?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

Viel Spaß beim Bieten und natürlich beim Minen war jetzt lange genug dabei
Natürlich funktioniert alles einwandfrei.

Deus

Was willst du für die 6990?
Mich würde auch interessieren was für eine 6990 das ist.

Grüße

So wieder nachgelegt.
Hat sich ja bis jetzt wirklich gelohnt

So habe mal wieder etwas nachgelegt

Mir würde es gefallen, wenn unter Handel noch ein Rechner wäre.
Er sollte folgendes können: ich will 0.2 BTC in z.B. bitcoinproject.net investieren und dann soll er ausrechnen wieviele aktien das sind.
Bis jetzt immer google dafür genutzt, nervt aber.
Unter Handel sollte auch der eigene Kontostand ersichtlich sein.
Es wäre auch gut wenn unter Depot steht zu welchem wert gekauft wurde und dann der Unterschied zum aktuellen Kurs ist + oder - betrag in BTC.
Vielleicht auch ein paar englische Seiten mit aufnehmen, dann könnte man besser dafür werben.
Dann muss aber die seite auf englisch sein.
Aber das Traden funktioniert super, hab schon ein paar mal gemacht.

Mir gefällt die Seite. Hab mal paar gekauft.
Leider noch nicht soviel los.