Security
Smart cards have been advertised as suitable for personal identification tasks, because they are engineered to be tamper resistant. The chip usually implements some cryptographic algorithm. There are, however, several methods for recovering some of the algorithm's internal state.
Differential power analysis involves measuring the precise time and electrical current required for certain encryption or decryption operations. This can deduce the on-chip private key used by public key algorithms such as RSA. Some implementations of symmetric ciphers can be vulnerable to timing or power attacks as well.
Smart cards can be physically disassembled by using acid, abrasives, or some other technique to obtain unrestricted access to the on-board microprocessor. Although such techniques obviously involve a fairly high risk of permanent damage to the chip, they permit much more detailed information (e.g. photomicrographs of encryption hardware) to be extracted.
Read more about this topic: Smart Card
Famous quotes containing the word security:
“It seems to me that our three basic needs, for food and security and love, are so mixed and mingled and entwined that we cannot straightly think of one without the others. So it happens that when I write of hunger, I am really writing about love and the hunger for it, and warmth and the love of it and the hunger for it ... and then the warmth and richness and fine reality of hunger satisfied ... and it is all one.”
—M.F.K. Fisher (b. 1908)
“Happiness is peace after strife, the overcoming of difficulties, the feeling of security and well-being. The only really happy folk are married women and single men.”
—H.L. (Henry Lewis)
“Modern children were considerably less innocent than parents and the larger society supposed, and postmodern children are less competent than their parents and the society as a whole would like to believe. . . . The perception of childhood competence has shifted much of the responsibility for child protection and security from parents and society to children themselves.”
—David Elkind (20th century)