As is known among cryptographers, the security of Elliptic Curve Digital Signature Algorithms (ECDAs) employed by the aforementioned cryptocurrencies is highly dependent on random data, which are known as nonces. The research further explains:
“It is well known that if an ECDSA private key is ever used to sign two messages with the same signature nonce, the long-term private key is trivial to compute [crack].”
The researchers claim to have successfully hacked hundreds of Bitcoin, some Ethereum, SSH (remote control for unix-like systems), HTTPS and one XRP private keys thanks to so-called biased nonces (with a low degree of randomness.) As the researchers explain, the consequences of such vulnerabilities are vast:
“In the case of cryptocurrencies, these keys give us, or any other attacker, the ability to claim the funds in the associated accounts. In the case of SSH or HTTPS, these keys would give us, or any other attacker, the ability to impersonate the end hosts.”
Still, the paper explains that such vulnerabilities can be prevented:
“All of the attacks we discuss in this paper can be prevented by using deterministic ECDSA nonce generation, which is already implemented in the default Bitcoin and Ethereum libraries.”
According to Ripple, deterministic nonce generation has also been part of their software since August 2015. This feature also makes addresses that interacted with the blockchain employing newer software libraries safe from this vulnerability.
While cryptography is far from perfect, centralized systems like exchanges and single computing systems are successfully attacked with success much more often than private keys, the research states.. The paper further notes that during the research, access has been obtained to only about $54 of BTC and $14 of XRP.
Also, recently news broke that a recent spate of ransomware attacks estimated to have earned hackers 705.08 Bitcoin ($2.5 million) likely came from Russian cybercriminals, not North Korean state-sponsored actors as initially thought.