Support for PKCS12 KeyStore in format in SunJCE provider requires that the algorithm id is one of the known OIDs registered with one of the security providers. Using an unknown OID results in java.security.NoSuchAlgorithmException.

It seems fitting that the algorithm id of SecretKey stored in the underlying KeyStore would be PKCS#7 data (1.2.840.113549.1.7.1).