Researchers Forged RSA Signatures Inside a Hardware Security Module Without Extracting the Key

• —The attack required about 2^32 (roughly 4 billion) signing requests and 1,380 CPU core-years
• —The key never left the hardware security module, yet signatures were still forged
• —Bitcoin and Ethereum use ECDSA/Schnorr, not RSA, so they are not directly affected
• —The authors say most modern RSA deployments with padding face no immediate threat