<p>I just purchased a pair of CryoBit cards and it occurred to me that, while I know how to send money to a cold storage wallet, I am not exactly sure how to send money out.  I assume I import the private key into an online wallet, like BlockChain, and then do a full sweep to another address in the BlockChain wallet.</p>

<p>But if I import the CryoBit private key doesn't that expose the private key on my CryoBit card, reducing the full trust of that card?  I've read on other answers that once a cold storage private key is imported into an online wallet that wallet should never be used again...  At $30 per CryoBit card that seems like an expensive waste to discard the card after one use.</p>

<p>Also, if I do import the private key on the CryoBit card into BlockChain, do I have to do a full sweep or can I just send some of the CryoBit private key funds out?</p>

<p>Say for example I have $1000 on my CryoBit card and I import the private key into BlockChain.  Then I send $500 to an external address leaving $500 on the CryoBit address.  Then to clean up the cold storage I delete the private key from BlockChain.  Will I still have a trustworthy cold storage wallet in CryoBit with the remaining $500?</p>

CC BY-SA 3.0
2014-06-06T06:09:51.537Z
The other answers don't address the concept of cold storage "cards" and what to do with them after importing the private keys.  They also don't talk about whether it's okay to send partial funds directly from the cold storage address without doing a full sweep of the funds into a different local wallet.
Dscoduc
CC BY-SA 3.0
2014-06-06T06:28:21.523Z
Yes, but there are other similar cards like [Bit-Card](http://www.bit-card.de/cards/encrypted-cards.html)
Dscoduc
CC BY-SA 3.0
2014-06-06T06:41:43.630Z
The private key is on the back but is encrypted with a passphrase.
Dscoduc
CC BY-SA 3.0
2014-06-30T20:53:11.670Z
What we have here is a terminology problem. Those cards, strictly speaking, are not cold storage. By definition, cold storage must never allow an unencrypted private key to touch an online system, which these cards don't do. When you spend from them, the (presumably online) spending device MUST decrypt the key. What you have here is just a non-paper version of a BIP38 encrypted Paper Wallet. This should be helpful: http://bitcoin.stackexchange.com/questions/19545/which-wallet-applications-implement-bip38-private-key-password-encryption
David Perry
<coldstorage>
Sending from CryoBit Cold Storage
Dscoduc
# Sending from CryoBit Cold Storage

(Asked by: username_0 on 2014-06-06)

I just purchased a pair of CryoBit cards and it occurred to me that, while I know how to send money to a cold storage wallet, I am not exactly sure how to send money out. I assume I import the private key into an online wallet, like BlockChain, and then do a full sweep to another address in the BlockChain wallet.

But if I import the CryoBit private key doesn't that expose the private key on my CryoBit card, reducing the full trust of that card? I've read on other answers that once a cold storage private key is imported into an online wallet that wallet should never be used again... At $30 per CryoBit card that seems like an expensive waste to discard the card after one use.

Also, if I do import the private key on the CryoBit card into BlockChain, do I have to do a full sweep or can I just send some of the CryoBit private key funds out?

Say for example I have $1000 on my CryoBit card and I import the private key into BlockChain. Then I send $500 to an external address leaving $500 on the CryoBit address. Then to clean up the cold storage I delete the private key from BlockChain. Will I still have a trustworthy cold storage wallet in CryoBit with the remaining $500?

**Tags:** coldstorage

> **Comments:**
> **username_0**: The other answers don't address the concept of cold storage "cards" and what to do with them after importing the private keys.  They also don't talk about whether it's okay to send partial funds directly from the cold storage address without doing a full sweep of the funds into a different local wallet.  
> **username_0**: Yes, but there are other similar cards like [Bit-Card](http://www.bit-card.de/cards/encrypted-cards.html)  
> **username_0**: The private key is on the back but is encrypted with a passphrase.  
> **username_1**: What we have here is a terminology problem. Those cards, strictly speaking, are not cold storage. By definition, cold storage must never allow an unencrypted private key to touch an online system, which these cards don't do. When you spend from them, the (presumably online) spending device MUST decrypt the key. What you have here is just a non-paper version of a BIP38 encrypted Paper Wallet. This should be helpful: http://bitcoin.stackexchange.com/questions/19545/which-wallet-applications-implement-bip38-private-key-password-encryption  

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## 0 answers

