Reading, writing and converting RSA keys in PEM, DER, PUBLICKEYBLOB and PRIVATEKEYBLOB formats This post finishes my epic about the implementation of RSA encryption. See the part I and part II of my post about RSA encryption for C++/Delphi (CryptoAPI) and PHP (OpenSSL) applications. The main problem we faced was incompatibility of key formats. CryptoAPI uses PRIVATEKEYBLOB and PUBLICKEYBLOB format