Regarding BouncyCastle dependency declaration, please see the “thirdpartylicenses.Aspose.Cells for Java.pdf” file in the release archive for your reference.
Please note, Bouncy Castle 1.6 is used in Aspose.Cells for Java.
thanks for the link to the Downloads section with the full zip also including the correct version of Bouncy Castle (old versions like this are quite hard to find on the internet ).
Before, I only managed to get access to the repository.aspose.com site which does not expose the zips.
Anyway, wouldn’t it be better to declare the dependencies explicitly in the Maven POM? After all, managing dependencies is what Maven is good for.