Android Question Connecting securely with HttpUtils2?

I want to make an app that can place trades on cryptsy.com and I'm hoping for some general guidance. The API website https://www.cryptsy.com/pages/api seems to be inclusive in stating what it needs. I was able to stumble around with example php program at the bottom of the page and got it to work, but I want to do that with B4A!

I am trying to use the HttpUtils2 library. I am using my API key with the Username method and private key with the Password method. I'm using PostString to call the API website and give my credentials. I believe it is the cryptsy website that returns this to my logs:

{"success":"0","error":"Unable to Authorize Request - Check Your Post Data"}

I am new to HttpUtils2 but I think my hang up is my private "sign" key. From the link I posted:

Sign — ALL POST data (param=val&param1=val1) signed by a secret key according to HMAC-SHA512 method. Your secret key and public keys can be generated from your account settings page.

An additional security element must be passed into the post:

nonce - All requests must also include a special nonce POST parameter with incrementing integer. The integer must always be greater than the previous requests nonce value.

Click to expand...

Does this mean I have send my signed key in an encrypted format? Is there a way to send a nonce POST?

Also, I have done a lot of googling but if someone could suggest a website that teaches a complete beginner what is going on when a PostString calls a website that would also be awesome.

Thanks