DKIM Record - What is the bit length generated?

DKIM Record - What is the bit length generated?

Came across a few articles similar to this one where it explains that 512-bit DKIM keys can be cracked:

https://wordtothewise.com/2012/11/how-long-is-your-dkim-key/

Just wondering how we can tell what the bit-length is of the DKIM records generated in zoho; and if they are 512-bit is there any way to generate a 1024 bit? Can we generate DKIM elsewhere and save them to a domain under 'Email Authentication' in the control panel?

Thanks