Chiasmus is a secret German government

block cipher In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called ''blocks''. Block ciphers are specified cryptographic primitive, elementary components in the design of many cryptographic protocols and ...

that was leaked by

reverse engineering Reverse engineering (also known as backwards engineering or back engineering) is a process or method through which one attempts to understand through deductive reasoning how a previously made device, process, system, or piece of software accompli ...

. It became notorious for its dilettant use in the BSI's software GSTOOL, which used it in insecure Electronic Codebook (ECB) mode and generated the key with a

pseudo random number generator A pseudorandom number generator (PRNG), also known as a deterministic random bit generator (DRBG), is an algorithm for generating a sequence of numbers whose properties approximate the properties of sequences of random numbers. The PRNG-generate ...

initialized to the current system time, which means an effective key length that can easily be broken by

brute force Brute Force or brute force may refer to: Techniques * Brute force method or proof by exhaustion, a method of mathematical proof * Brute-force attack, a cryptanalytic attack * Brute-force search, a computer problem-solving technique People * Brut ...

. The BSI tried to prevent the publication of these findings with legal threats. Chiasmus seems to be resistant against the most common cryptographic attacks (

linear Linearity is the property of a mathematical relationship (''function'') that can be graphically represented as a straight line. Linearity is closely related to '' proportionality''. Examples in physics include rectilinear motion, the linear r ...

and

differential cryptanalysis Differential cryptanalysis is a general form of cryptanalysis applicable primarily to block ciphers, but also to stream ciphers and cryptographic hash functions. In the broadest sense, it is the study of how differences in information input can aff ...

), but a lot slower than the openly available state of the art ciphers such as AES.

References

External links

* http://prezi.com/bzyvzzdsxtkm/ubicrypt-chm/ * http://janschejbal.wordpress.com/tag/chiasmus/ * https://events.ccc.de/congress/2013/Fahrplan/events/5307.html {{Cryptography navbox , block Block ciphers

See also

References

External links