ssss.manpage.xml

shamir密钥共享机制的c语言实现

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<manpage name="ssss" section="1" 
  desc="Split and Combine Secrets using Shamir's Secret Sharing Scheme.">

<synopsis>
      <cmd>ssss-split -t <arg>threshold</arg> -n <arg>shares</arg> [-s
      <arg>level</arg>] [-w <arg>token</arg>] [-x] [-q] [-Q]</cmd>
      <cmd>ssss-combine -t <arg>threshold</arg> [-x] [-q] [-Q] [-D]</cmd>
</synopsis>

<description>
<p>ssss is an implementation of Shamir's Secret Sharing Scheme. The
program suite does both: the generation of shares for a known secret,
and the reconstruction of a secret using user-provided shares.</p>
</description>

<section name ="Commands">
      <p><opt>ssss-split</opt>: prompt the user for a secret and generate a set of
      corresponding shares.</p>
      
      <p><opt>ssss-combine</opt>: read in a set of shares and reconstruct
      the secret.</p>
</section>

<options>

      <option>
<p><opt>-t <arg>threshold</arg></opt></p> <optdesc><p>The number of
      shares necessary to reconstruct the secret.</p></optdesc>
    
</option>

      <option>
<p><opt>-n <arg>shares</arg></opt></p>
<optdesc>
      <p>The number of shares to be generated.</p>
</optdesc>
</option>      
      <option><p><opt>-s <arg>level</arg></opt></p>
<optdesc>
      <p>The scheme's security level in bits. It is an upper bound for
      the length of the shared secret (shorter secrets are
      padded). Allowed values are 80, 112, 128, 192, 256, 512 and
      1024. The default is 128.</p>
</optdesc>
</option>      
      
      <option><p><opt>-w <arg>token</arg></opt></p>
<optdesc>
      <p>Text token to name shares in order to avoid confusion in case one
      utilizes secret sharing to protect several independent secrets. The
      generated shares are prefixed by these tokens.</p>
</optdesc>
</option>      
      
      <option><p><opt>-x</opt></p>
<optdesc>
      <p>Hex mode: use hexadecimal digits in place of ASCII characters for
      I/O. This is useful if one wants to protect binary data, like
      block cipher keys.</p>
</optdesc>
</option>      
      
      <option><p><opt>-q</opt></p>
<optdesc>
      <p>Quiet mode: disable all unnecessary output. Useful in scripts.
      </p>
</optdesc>
</option>      
      <option><p><opt>-Q</opt></p>
<optdesc>
      <p>Extra quiet mode: like <opt>-q</opt>, but also suppress
warnings.</p>
</optdesc>
</option>      

      <option><p><opt>-D</opt></p>
<optdesc>
      <p>Disable the diffusion layer added in version 0.2. This option is
      needed when the shares were generated with ssss version 0.1.</p>
</optdesc>
</option>      
</options>

<section name="Example">
<p>
        Suppose you want to protect your login password with a set of ten
        shares, in such a way that any three of them can reconstruct the
        password, simply run the command
</p>

<p>
          ssss-split -t 3 -n 10 -w passwd
</p>

<p>
        To reconstruct the password pass three of the generated shares
        (in any order) to
</p>

<p>
          ssss-combine -t 3
</p>
</section>

<section name="Author">
        This software (v0.3) was written in 2005 by B. Poettering (ssss AT
        point-at-infinity.org). Find the newest version of ssss on the
        project's homepage: <url
        href="http://www.point-at-infinity.org/ssss/"/>. 
</section>

<section name="Further reading">
        <url href="http://en.wikipedia.org/wiki/Secret_sharing"/>
</section>


</manpage>