Blockchain.info Hacker "Johoe" Returns 255 BTC, Says 1019 Addresses Compromised

An "ethical" hacker has returned 255.04297985 BTC taken from users in Blockchain Blockchain Blockchain comprises a digital network of blocks with a comprehensive ledger of transactions made in a cryptocurrency such as Bitcoin or other altcoins.One of the signature features of blockchain is that it is maintained across more than one computer. The ledger can be public or private (permissioned.) In this sense, blockchain is immune to the manipulation of data making it not only open but verifiable. Because a blockchain is stored across a network of computers, it is very difficult to tampe Blockchain comprises a digital network of blocks with a comprehensive ledger of transactions made in a cryptocurrency such as Bitcoin or other altcoins.One of the signature features of blockchain is that it is maintained across more than one computer. The ledger can be public or private (permissioned.) In this sense, blockchain is immune to the manipulation of data making it not only open but verifiable. Because a blockchain is stored across a network of computers, it is very difficult to tampe Read this Term.info's most recent security flaw. Named "johoe" on the Bitcoin Bitcoin While some may still be wondering what is Bitcoin, who created Bitcoin, or how does Bitcoin work, one thing is certain: Bitcoin has changed the world.No one can remain indifferent to this revolutionary, decentralized, digital asset nor to its blockchain technology.In fact, we’ve gone a long way ever since a Florida resident Laszlo Hanyecz made BTC’s first official commercial transaction with a real company by trading 10,000 Bitcoins for 2 pizzas at his local Papa John’s.One could now argue that While some may still be wondering what is Bitcoin, who created Bitcoin, or how does Bitcoin work, one thing is certain: Bitcoin has changed the world.No one can remain indifferent to this revolutionary, decentralized, digital asset nor to its blockchain technology.In fact, we’ve gone a long way ever since a Florida resident Laszlo Hanyecz made BTC’s first official commercial transaction with a real company by trading 10,000 Bitcoins for 2 pizzas at his local Papa John’s.One could now argue that Read this Term Talk forum, he explained:

"There were a large bunch of new broken addresses today (several 100s in one day). I took the liberty of saving some funds before they got swiped by others. If you can convince me that they belong to you (signing a message with the address is obviously not enough; the private key is already known), I will send the funds back."

The hacker posted a page with 1019 compromised addresses, in line with Blockchain.info's recent announcement that several hundred addresses may have been affected.

"Joehoe" went on to post a photo showing him returning the funds with his Trezor wallet. After initially offering to return them to each user, they have been instead sent to Blockchain.info, who will validate claims.

Ethical (white-hat) hacking is a contentious practice, at times employed by companies or even governments to test the robustness of security measures. Legal experts have pointed out that such practice is prohibited according to the letter of the law.

Blockchain.info said that the most recent security flaw arose from wallets being created with recycled 'R-values' in formulas that generate random numbers, allowing the private keys to be calculated from the public keys.

For users incurring losses due to earlier security flaws, Blockchain.info said they will be compensated out of its own pocket, acknowledging their fault in the matter.