Yes, you are right. I have to think how to change the code to restore the unsurprising behaviour. Your FIPS arguments btw are void, the referenced security policy does not apply to us, and would actually only allow keysizes 2048, 3072 and 4096 bits. No uneven keylengths, no other keylengths. Also the FIPS 186-4 standard has P - Q distance constraints that just cannot be met by uneven bit length keys. ( http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf , section B 3.1) Again, I will see that I can change the code to allow uneven lengths in non-FIPS approved mode. :/