AES-GCM is in NSA Suite B and AES-CCM and AES-EAX aren't. IIRC, EAX isn't even NIST approved. GCM is parallelizable, and CCM and EAX aren't. New Intel processor

AES-GCM is in NSA Suite B and AES-CCM and AES-EAX aren't. IIRC, EAX isn't even NIST approved. GCM is parallelizable, and CCM and EAX aren't. New Intel processors have special support for GCM, which should makes GCM notably faster. http://www.cryptopp.com/wiki/EAX_Mode http://www.cryptopp.com/wiki/EAX_Mode has a very brief but good summary of the advantages of GCM over CCM and EAX. Also see this slide (warning: PPT): http://www.cryptopp.com/w/images/c/ce/AtE-Comparison.ppt http://www.cryptopp.com/w/images/c/ce/AtE-Comparison.ppt