Level 4 isn't exactly a walk in the park; YubiCo have said their excuse is cost. They're listed as achieving Level 1 according to http://csrc.nist.gov/groups/ST

Level 4 isn't exactly a walk in the park; YubiCo have said their excuse is cost. They're listed as achieving Level 1 according to http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140val-all.htm#2267 http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140val-... But this list spans 20 years of vendor certifications, and I count only 19 entries out of 2277 which have achieved Level 4. Edit: Oops, actually only Overall Level 1. http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140sp/140sp2267.pdf http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140sp/1...