8Oca
Why does the Public Key Info field in an X509 certificate for EC indicate the algorithm
The Subject Public Key Info field can have a value like ECDSA_P256 or ECDH_P256 when ECC is used.
Why is it not sufficient to specify "ECC_P256"? In other words, why is it not enough to specify just the curve parameters (like prime p, generator point G, etc.). This would sufficiently describe the key mathematically.
Depending on how the certificate is used (e.g. in the context of TLS or digital signature), the two parties anyway need to agree on an algorithm. It doesn't seem like it would need to be hardcoded in the Public Key Info field.
With RSA - there is no such distinction and I can, in theory, use the same certificate for different use cases allowed by the purpose field in the x509 certificate.
