5
$\begingroup$

This is an honest question regarding terminology. I believe that I understand why one mode to use a block cipher is called a codebook. But I wonder why electronic as a work appears here?

Is it fair to say this is just a fancy/stylish addition? Should it relfect that often encyption is used with electrical devices? Would ECB be impossible for a mechanic setup?

Improve this question
$\endgroup$

1 Answer 1

Reset to default
6
$\begingroup$

In a paper codebook, plaintext words (perhaps arranged alphabetically like in a dictionary) lead to a replacement word. Codebook Cipher for Telegraphic Correspondence — a code book used by Union General Joseph Hooker’s code clerk. Source: wikipedia.

A block cipher implemented using electronic circuitry (as DES was initially) does the equivalent, with block instead of word, and new key instead of new book. That's thus an electronic codebook. The operating mode based solely only this feature is Electronic CodeBook.

It would be possible to implement a block cipher using non-electronic means, e.g. mechanic of even manual; and operate it in ECB mode. Fact is, this was not done on a large scale. Before DES, mechanical ciphers tended to operate on a letter-by-letter basis, not something wide comparable to a word.

Improve this answer
$\endgroup$
3
  • $\begingroup$ Would that not mean that naming it electronic simply for one possible implementations (even though a common one) is rather misleading idea? It seems at least you suggest that ECB is used as a term for somehting which could be implemented not to electronics-wise? $\endgroup$
    – humanityANDpeace
    Commented Nov 11, 2014 at 10:09
  • $\begingroup$ Should we include something like "keyed block cipher = permutation = codebook"? $\endgroup$
    – Maarten Bodewes ♦
    Commented Aug 1, 2021 at 21:03
  • $\begingroup$ @humanityANDpeace Nobody in their right mind is going to implement a block cipher in a mechanical device, let alone calculate the output by hand. This is a rather theoretical issue. You can however e.g. implement it using a FPGA instead of a CPU, so I think that "electrical" is precisely the right term. $\endgroup$
    – Maarten Bodewes ♦
    Commented Aug 1, 2021 at 21:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.