Generating stoken in PHP

We are struggling to generate a valid stoken in PHP which works as described here: http://bit.ly/1RfbkAd We already tried multiple AES encryption methods with pkcs5 padding on and off etc. but it doesn't seem to work. We always get "invalid token" as response. The java code example works. Is there example code for PHP to generate this stoken? -- You received this message because you are subscribed to the Google Groups "reCAPTCHA" group. To unsubscribe from this group and stop receiving emails from it, send an email to recaptcha+unsubscribe@googlegroups.com. To post to this group, send email to recaptcha@googlegroups.com. Visit this group at http://bit.ly/1dkFnYd. For more options, visit http://bit.ly/P65DvS.