Blockchain’s fundamental design is based upon us having no access to customer funds or keys. This is achieved by making all transactions occur in the end-user’s browser, “client-side” with open-source and auditable software. We at Blockchain never store unencrypted keys, passwords, bitcoins or the have the ability to create transactions. This ensures that users’ bitcoins are not only secure from a broad-based attack on Blockchain, but are even secure from Blockchain and that’s deliberate. We don’t control your bitcoins; you do.
Blockchain has always recommended that users store their bitcoins in such a way as to maintain control and ownership of their keys. Custodial accounts, like those used by Mt. Gox, where other people hold the keys to your bitcoins are risky. Instead, customers should use services like Blockchain.info, where keys are decrypted in the browser, not held on the servers. Alternatively, use a desktop client such as Armory, Bitcoin-Qt, Multibit or Electrum. All of these store the keys in a local, encrypted file that is not shared with any servers or held by anyone else.
Last night, we were shocked to find out about Mt. Gox’s insolvency, as they appear to have committed a grievous breach of trust against their customers.
The Blockchain staff will continue to collaborate with other industry leaders to establish better controls to ensure that events like this are not repeated. We are hopeful that together we can create a more trustworthy industry for the benefit of all existing and future Bitcoin holders.