Birthday attacks are used against which of the following？（）

A. uses symmetric crypto for keys distribution
B. uses symmetric crypto for proof of origin
C. uses symmetric crypto for fast encrypted/decryption
D. uses asymmetric crypto for message confidentiality
E. uses symmetric crypto to transmit the asymmetric keys that is thenused to encrypt a session

A. at the untrusted interfacein the inbound direction
B. atthe untrusted interface in theoutbounddirection
C. at thetrusted interface inthe inbound direction
D. at the trusted interface in the outbound direction
E. at the trusted and untrusted interfaces in the inbound direction
F. at the trusted and untrusted interfaces in the outbounddirection