Hack

is a hardware and/or software that is designed to defeat a data protection scheme. (verb) To create such hardware/software.

Hacker

is the designer of a hack.

Hardware Security Module

is a hardware component dedicated to store and handle cryptographic secrets. The security of these modules is extreme. They typically are compliant with FIPS140 and Common Criteria EAL4+. For instance, HSM physically erases the stored cryptographic secrets if it decides that it is under attack. For this decision, it uses many physical captors, such voltage drop, clock frequency, light detector, passivation detectors, … The main use of HSM is to store the root private key of a PKI infrastructure.

Hash function

is a transformation that takes a variable size input m and returns a fixed-length string called the hash value h. ( h=H(m)). In cryptography, hash functions should have additional properties:

• H(x) is easy to calculate whatever value of x.
• H(x) is one way, i.e., hard to invert. Knowing h, it is unfeasible to find out x.
• H(x) is collision free. It is computationally unfeasible to find x, and y so that H(x)=H(y)

SHA is the most famous and used hash function today.

Hoax

is a junk e-mail that carries a fake alert message about a security breach. The message recommends distributing this message as widely as possible. This may generate some mail congestion. This is a primitive manual version of the Melissa type virus.

Honey Net

is a fake network of computers whose objective is either to trick attackers or to study their behaviour.

HSM

see Hardware Security Module.