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==task specifics== Hi,
- What is goal of the task?
- How does one know one has completed the task?
- Do you have sample tests and sample output?
- Thanks. --[[User:Paddy3118|Paddy3118]] 20:22, 31 August 2012 (UTC)
:* The goal of the task is the comparison of programming languages for the implementation of some specific cryptographic algorithm, originally designed for efficient execution on 32-bit and 64-bit machines (though created in the 70's), while it operates with a 4-bit block; comparison of low-level with high-level languages in this aspect for the sake of brevity and clarity of code execution speed, consumption of computer resources and so on.
:* The task can be considered solved if the algorithm is implemented only true converts the input data.
:* Verification example can be used as follows:
::the input is a text block size of 8 bytes:
::and item key, size 4 bytes:
::Incoming text block is divided into two parts:
::First we add modulo 232 with the received key element, the result is
::Further, in this block is replaced with the replacement table. Are replaced by:
::Finally, we obtain
::Next is the cyclic shift of reading towards senior level by 11 bits:
::This value is made up bit by bit modulo 2 with the second part on the input 8-bit block, the result is
::Now is 8-byte block of data in the first part of which is located just obtained value, and the second - the first part was on the input 8-byte block. The resulting value
::and will be the result of the step.
: [[User:Русский|Русский]] 18:54, 1 September 2012 (UTC)
Sonia, you are almost there. The second part of the output is actually just a copy of the other part of the input. See http://en.wikipedia.org/wiki/Feistel_cipher or my Perl 6 solution. —[[User:Edwin|Edwin]] 13:30, 6 October 2012