Transfering from SecByteBlock to DSA::PrivateKey is not working

[naushadck]

Created privatekey from
SecByteBlock privateKey(ecdh.PrivateKeyLength());

But unable to transfer the SecByteBlock to
RSA::PrivateKey or
ECDSA<ECP, CryptoPP::SHA256>::Signer.

[Coralesoft]

The issue here is a fundamental misunderstanding about cryptographic key types and formats

[naushadck]

No proper workable example/solution was found except (wiki/Elliptic_Curve_Digital_Signature_Algorithm).

One proper explanation/solution for the transformation is found. The same is given below.
(https://stackoverflow.com/questions/27232053/creation-of-ecdsa-private-key-given-curve-and-private-exponent)

The answer is detailed on the ECDSA wiki page, but its not readily apparent.

string exp = "E4A6CFB431471CFCAE491FD566D19C87082CF9FA7722D7FA24B2B3F5669DBEFB";
exp.insert(0, "0x");

I hope this may help somebody.