Encryption Algorithm Footprint

["fooyu" <security () fooyu com>]

I am auditing one of my critical service system. This system provides our users a method of stock exchange. By using 
ethereal I found the data packets was encypted like in SSL. Next I found the private key in my server and encypted 
symmetric key payload in the captured packets. After successfully decrypting the 16- bytes symmetric key, I test many 
encryption algorithm to decrypted the captured ciphertext, but all failed.

I want to know if encryption algorithm has footprint. Is there any technica to find which encryption algorithm it used?

Thank you all and Happy Chinese New year!

Haiyan Chen

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[security () fooyu com]
www.fooyu.com
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