Hi all... I currently have a working SIM MD5 solution and am updating to SHA512.  I believe that I have walked through the necessary steps as outlined here ( https://support.authorize.net/s/article/Do-I-need-to-upgrade-my-transaction-fingerprint-from-HMAC-MD... ), however continue to receive an Error Code 99.

Essentially, the only changes are, as I read them
 -- to request a Signature Key, change to binary, use this as the HMAC key
 -- change the algorithm from HMACMD5 to HMACSHA512

MD5 Solution:
<cfset digest=HMAC("#authNetLogin#^#sequence#^#fp_timestamp#^#x_amount#^","#authNetTrnxKey#","HMACMD5") />

SHA512:
<cfset authNetHexSignatureKey = "REMOVED_FROM_CODE" />
<cfset authNetBinarySignatureKey = toBinary(authNetHexSignatureKey) />
<cfset digest=HMAC("#authNetLogin#^#sequence#^#fp_timestamp#^#x_amount#^","#authNetBinarySignatureKey#","HMACSHA512")>

The existing Error 99 tool ( https://developer.authorize.net/api/reference/responseCode99.html ) appears to be for use in the old MD5 method.  Is there another tool for this?

I have looked at the data being posted using the dump tool here ( http://developer.authorize.net/bin/developer/paramdump ) and everything LOOKS ok.

Any assistance would be appreciated.

Thanks.