"Cold Storage is the act of sending Bitcoins to an offline wallet address. Access to withdraw these funds must be by a human being and with a computer that is never plugged into the internet. This guarantees that a hacker cannot steal the wallet through the internet. This is done with transaction signing and USB keys to transfer the signed transaction from the offline computer to the online Bitcoin network. Over $500,000USD was stolen from the Exchanges Bitcoinica and Bitfloor by hackers because they did not use cold storage. VirtEx uses cold storage on approximately 80% of customer funds.
We keep the remaining 20% in a server ‘hot’ wallet to allow the small daily BTC withdrawal activity to be instant. If the amount of your withdrawal is too large, you will be required to wait for a human to perform a cold storage withdrawal of your funds. We have many different cold storage wallets and use multi-signature authentication so there is never just one person who can access cold storage and large amounts. You can even choose to place 100% of your funds in cold storage with us; however you will not be able to trade the funds unless you withdraw them from cold storage. This feature is coming soon."
It's not an excange, but does anyone know how secure blockchain.info's wallets are? Everything I've read says they're very secure, but I haven't seen any unbiased experts say that...
"Cold Storage is the act of sending Bitcoins to an offline wallet address. Access to withdraw these funds must be by a human being and with a computer that is never plugged into the internet. This guarantees that a hacker cannot steal the wallet through the internet. This is done with transaction signing and USB keys to transfer the signed transaction from the offline computer to the online Bitcoin network. Over $500,000USD was stolen from the Exchanges Bitcoinica and Bitfloor by hackers because they did not use cold storage. VirtEx uses cold storage on approximately 80% of customer funds.
We keep the remaining 20% in a server ‘hot’ wallet to allow the small daily BTC withdrawal activity to be instant. If the amount of your withdrawal is too large, you will be required to wait for a human to perform a cold storage withdrawal of your funds. We have many different cold storage wallets and use multi-signature authentication so there is never just one person who can access cold storage and large amounts. You can even choose to place 100% of your funds in cold storage with us; however you will not be able to trade the funds unless you withdraw them from cold storage. This feature is coming soon."