Google reCaptcha is, frankly, very poor. Two text strings are shown, one of which is ALWAYS unreadable. OK, only the readable one is really needed, but do you think the vast majority know this? And visitors with poor eyesight? How do they cope?

The DMXZONE reCaptcha module should also include one or more alternatives, such as the simple numerical calculation. Such as "5 + 3 =". There are other alternatives using text strings that are actually readable!

Without doubt the best alternative is zCaptcha which uses icons and can be bought from Code Canyon for about $10. I use it all the time.