This is about using the same key on multiple messages. In these ancient times, one machine had to issue keys to users independently of these users then needing them to encrypt something. An organisational problem rather than a problem of the algorithm. Today it is simple enough that the program encrypts and generates the key in one run. Although as we can see from the amount of confusion in this thread -- even intelligent people have difficulty understanding what is breakable or not and why. My impression is that the OTP had a bad rep. from these incidents. Even more confusing for many is of course: why the more recent use of number theory (modulo) in also public key encryption as opposed to using XOR? I have tried to explain it from my own perspective because I can find no similar explanations online - just more confusing posts in other sites. In one case I saw a lengthy answer to this very question on stack-exchange that failed to even try to actually answer the question but waffled about what was popular with cryptographers instead.

In reply to Re^6: crypto with core modules only by TheloniusMonk
in thread crypto with core modules only by morgon

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.