github.com/cryptoballot/rsablind (go): Package rsablind is the RSA Blind.  RSA Blind Signing using a Full Domain Hash  In cryptography, a blind signature is a form of digital signature in which the content of a message is disguised (blinded) before it is signed. The entity signing the message does not know the contents of the message being signed.  • This library has not undergone a security review or audit and should not be used in production code.  • The key used to sign the blinded messages should not be used for any other purpose. Re-using this key in other contexts opens it up to attack.  • Use the Full-Domain-Hash package (https://github.com/cryptoballot/fdh (https://github.com/cryptoballot/fdh)) to expand the size of your hash to a secure size. You should use a full-domain-hash size of at least 1024 bits, but bigger is better. However, this hash size needs to remain significantly smaller than your key size to avoid RSA verification failures. A good rule of thumb is to use 2048 bit keys and 1536 bit hashes, or 4096 bit keys and 3072 bit hashes (hash size is 3/4 the key size).  • Because we use a full-domain hash size that is less than the key size, this scheme is theoretically open to an Index Calculation Attack (see http://www.jscoron.fr/publications/isodcc.pdf (http://www.jscoron.fr/publications/isodcc.pdf)). However, with a large enough RSA key (recommended 2048 bits or larger), and a large enough full-domain-hash (1024 bits or larger) this attack in infeasable.  Example
Keywords: blind-signatures|cryptography|full-domain-hash|golang|rsa|rsa-signature