title: BouncyCastle updated pgp key now getting checksum mismatch error
body: <p>I have a utility that is using the BouncyCastle.Crypto dll (version 1.7.4, runtime version 1.1.4), in order to decrypt a file that is given to it by another system.</p>
  
  <p>I just updated the pgp key (and provided the encryptor with the new public key). The new key uses 4096 bit RSA encryption and has a 24 character password, which are the only differences I can think of between the new key and the old key. The old key used I believe 2048 bit encryption with a 7 character password. </p>
  
  <p>When I attempt to decrypt a file the process is now failing when calling the PgpSecretKey.ExtractPrivateKey(char[] passPhrase) function, provided by BouncyCastle. The error is "Checksum mismatch at 0 of 20."
  The weird part is that the first time I tested it worked fine, then with no changes it began failing. I have tried with multiple encrypted files.</p>
  
  <p>Since it's such an old version of BouncyCastle and this particular permutation of the ExtractPrivateKey function is no longer in use I am finding it difficult to locate relevant information. Any thoughts are appreciated.</p>