To accurately assess the applicability of Bleichenbacher's attack for the specific case you mentioned—solving a hidden number problem with less than one-bit nonce leakage—you need to consider the details of the algorithm, the cryptographic scheme involved, and any relevant vulnerabilities. However, based on the information provided, it's difficult to determine the exact scenario you're referring to.
Bleichenbacher's attack is a known vulnerability that primarily affects RSA-based encryption schemes, particularly those using the PKCS#1 v1.5 padding scheme. It allows an attacker to decrypt ciphertexts and potentially extract the private key.
On the other hand, "spec256k1" refers to the elliptic curve secp256k1, which is commonly used in various cryptographic algorithms such as Bitcoin. However, it does not directly relate to Bleichenbacher's attack or hidden number problems.
To provide a more accurate answer, please provide additional context or clarify the specific scenario or cryptographic scheme you are referring to.