Index of /~bugbee/crypto/salsa20

 Name                    Last modified       Size  Description

 Parent Directory        06-Mar-2008 22:41      -  
 Salsa20example1.java    02-Jul-2007 22:05     8k  
 hotSalsa-v1.py          03-Jul-2007 13:52     6k  
 pySalsa20-v3.zip        20-Apr-2007 23:02    16k  

    Salsa20: a Fast Streaming Cipher
    --------------------------------

    Salsa20 is a fast stream cipher written by Daniel Bernstein 
    that basically uses a hash function to create a stream that 
    is XORed on the data making for very fast encryption and 
    decryption.  
    
        design strength    128 bits
        key length         128 or 256 bits, exactly
        IV, aka nonce      64 bits, always
        chunk size         must be in multiples of 64 bytes
    
    Salsa20 has two reduced versions, 8 and 12 rounds each.  The 
    12-round reduced version, Salsa20/12, is a "winner" of the 
    EU eSTREAM competition.
    
    ...and Salsa20 is "free for any use".  
    
    
    pySalsa20: a Python wrapper for Salsa20
    ---------------------------------------

    pySalsa20.py is a simple Python ctypes wrapper.  Salsa20 is 
    as it's name implies, 20 rounds, but there are two reduced 
    versions, 8 and 12 rounds each.  Because the APIs are 
    identical, pySalsa20 is capable of wrapping all three 
    versions (number of rounds hardcoded), including a special 
    version that allows you to set the number of rounds with a 
    set_rounds() function.  Source modification is preferred, 
    but one easy way to get Salsa20/12 is to call set_rounds(12). 
    
    Be sure to compile the version of your choice as a shared 
    library (not as a Python extension), name and install it as 
    libsalsa20.so.
    
      Usage:
        from pySalsa20 import Salsa20
        s20 = Salsa20(key, IV)
        dataout = s20.encryptBytes(datain)   # same for decrypt
    
      One benchmark (10 MB):
        1.5GHz PPC G4     102/97/89 MB/sec for 8/12/20 rounds
        AMD Athlon 2500+   77/67/53 MB/sec for 8/12/20 rounds
          (memory only, no I/O, and before Python GC kicks in)
    
    This is EXPERIMENTAL software and intended for educational 
    purposes only.  To make experimentation less cumbersome, 
    pySalsa20 is also free for any use.      
    
    THIS PROGRAM IS PROVIDED WITHOUT WARRANTY OR GUARANTEE OF
    ANY KIND.  USE AT YOUR OWN RISK.  
    
    Enjoy,
      
    Larry Bugbee
    bugbee@seanet.com
    April 2007
    rev Dec 2008

    
    References:
    -----------
      http://en.wikipedia.org/wiki/Salsa20
      http://en.wikipedia.org/wiki/Daniel_Bernstein
      http://cr.yp.to/djb.html
      http://www.ecrypt.eu.org/stream/salsa20pf.html
      http://www.ecrypt.eu.org/stream/p3ciphers/salsa20/salsa20_p3source.zip
     
    Prerequisites:
    -------------
      - Python 2.5 (or 2.4 with ctypes added)
      - gcc 4.x (gcc 3 should work)
    
    Installation:
    -------------
      Compile provided .c source (set_rounds() mod included) or 
      download salsa20_p3source.zip (see refs) and compile (you 
      may want to apply the changes for set_rounds(), or not ;-)
        PPC MacOSX:
          export MACOSX_DEPLOYMENT_TARGET=10.4
          gcc -fPIC -maltivec -O3 -dynamic -bundle          \
                    -undefined dynamic_lookup               \
                    -o libsalsa20.so  ecrypt-altivec-ppc.c
        Linux:
          gcc -fPIC -O3 -shared -o libsalsa20.so  ecrypt-linux.c
    
        Windows:
          see http://buggywhip.blogspot.com/2007/07/making-simple-dlls-simply.html
    
      Install libsalsa20.so:
          sudo cp libsalsa20.so /usr/local/lib   # Mandriva wanted /usr/lib
      
      Quick test:
        python pySalsa20.py
    
      Install pySalsa20.py:
        sudo python setup.py install
    
    ------------------------------------------------------------------------
    ------------------------------------------------------------------------
    ------------------------------------------------------------------------