crypt

 

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 User Commands                                            crypt(1)
 
 
 


NAME
      crypt - encode or decode a file
 


SYNOPSIS
      crypt [ password ]
 


DESCRIPTION
      crypt encrypts and decrypts the contents of  a  file.  crypt
      reads  from  the  standard  input and writes on the standard
      output.  The password is a key  that  selects  a  particular
      transformation.   If  no  password is given, crypt demands a
      key from the terminal and turns off printing while  the  key
      is being typed in. crypt encrypts and decrypts with the same
      key:
 
 
           example% crypt key<clear.file> encrypted.file
           example% crypt key<encrypted.file | pr
 
 
      will print the contents of  clear.file.
 
      Files encrypted by crypt are compatible with  those  treated
      by the editors ed(1), ex(1), and vi(1) in encryption mode.
 
      The security of encrypted files depends  on  three  factors:
      the  fundamental method must be hard to solve; direct search
      of the key space must be infeasible; "sneak paths" by  which
      keys or cleartext can become visible must be minimized.
 
      crypt implements a  one-rotor  machine  designed  along  the
      lines  of  the  German Enigma, but with a 256-element rotor.
      Methods of attack on such machines are  widely  known,  thus
      crypt provides minimal security.
 
      The transformation of a key into the  internal  settings  of
      the  machine  is deliberately designed to be expensive, that
      is, to take a substantial fraction of a second  to  compute.
      However,  if  keys  are restricted to (say) three lower-case
      letters, then encrypted files can be read by expending  only
      a substantial fraction of five minutes of machine time.
 
      Since the key is an argument to the  crypt  command,  it  is
      potentially visible to users executing ps(1) or a derivative
      command.  To minimize this possibility, crypt takes care  to
      destroy  any  record  of the key immediately upon entry.  No
      doubt the choice of keys  and  key  security  are  the  most
      vulnerable aspect of crypt.
 


FILES
      /dev/tty"
            for typed key
 
 
 
 SunOS 5.8           Last change: 14 May 1997                    1
 
 
 
 
 
 
 User Commands                                            crypt(1)
 
 
 


ATTRIBUTES
      See attributes(5) for descriptions of the  following  attri-
      butes:
 
      ____________________________________________________________
     |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
     |_____________________________|_____________________________|
     | Availability                | SUNWcsu                     |
     |_____________________________|_____________________________|
 
 


SEE ALSO
      ed(1), ex(1), ps(1), vi(1), attributes (5)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 SunOS 5.8           Last change: 14 May 1997                    2
 
 
 

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