What type of attacks occurs when a smartcard is operating under normal physical conditions, but
sensitive information is gained by examining the bytes going to and from the smartcard?

A.
Physical attacks.

B.
Logical attacks.

C.
Trojan Horse attacks.

D.
Social Engineering attacks.

Explanation:
Logical attacks occur when a smartcard is operating under normal physical conditions, but sensitive
information is gained by examining the bytes going to and from the smartcard. One example is the
so-called “timing attack” described by Paul Kocher. In this attack, various byte patterns are sent to
the card to be signed by the private key. Information such as the time required to perform the
operation and the number of zeroes and ones in the input bytes are used to eventually obtain the
private key. There are logical countermeasures to this attack but not all smartcard manufacturers
have implemented them. This attack does require that the PIN to the card be known, so that many
private key operations can be performed on chosen input bytes.