A Clever RSA Attack Fooled a Hardware Vault—Here's What It Means for Crypto
Researchers showed a practical attack against RSA signing when a hardware security module is forced to sign unformatted numbers. By querying the device about 4 billion times and analyzing the outputs, they could forge signatures without extracting the private key. The setup used a test key and disabled FIPS mode, so it does not directly threaten properly configured modern systems. The result affects RSA, not Bitcoin or Ethereum’s elliptic-curve signatures. It mainly demonstrates that some key-protection assumptions fail if a signing oracle is exposed. The work also matters for blind-signature systems that intentionally provide such oracles. The paper is a preprint and is framed as another reason to keep migrating away from RSA during the post-quantum transition.
