Merge pull request #1 from OKullmann/CS-354

Update after Latex review
Interim.tex and PDF uploaded

Interim document has been uploaded so it can be reviewed on LaTeX, as
well as the final pdf form of it (for reference).
Dissertation.tex is uploaded. (interim required a different writing
style compared to the report and therefore is different)
Bibliography.bib has up to date references
merged document

introduction and interim
Update of Block ciphers

Block ciphers of arbitrary lengths have been explained
Permutations have been defined with an example
Weak keys have been introduced
It has been shown how two different keys do not map to the same output
(Strong property)
Update with duplicate key

Weak keys have been defined more clearly
Improvements on figures throughout the document (easier to refer to a
table of image)
"\newline" has been removed everywhere, were needed
packages have been introduced to handle subtables
Definition and example of duplicate key has been given
Removing the error with BlockCipher.png.

This is not a final solution.
Problem is that png with "bounding box" is needed.
One could eps instead.
Corrected bibtex-entry.