Encryption source code with md5

[geremy condra]

On Sun, Apr 4, 2010 at 6:03 PM, Robert Kern <robert.kern at gmail.com> wrote:
> On 2010-04-03 20:21 , Lawrence D'Oliveiro wrote:
>>
>> In message<4baf3ac4$0$22903$e4fe514c at news.xs4all.nl>, Irmen de Jong wrote:
>>
>>> On 28-3-2010 12:08, Lawrence D'Oliveiro wrote:
>>>
>>>> Don’t use MD5.
>>>
>>> Also, md5 is not an encryption algorithm at all, it is a secure hashing
>>> function.
>>
>> You can use hash functions for encryption.
>
> You can *build* an encryption algorithm out of hash functions as a
> primitive, yes. Paul Rubin's p3.py is an example of using SHA-1 to build an
> encryption algorithm:
>
>  http://www.nightsong.com/phr/crypto/p3.py
>
> However, a hash function is not an encryption algorithm itself. One does not
> "encrypt with md5" as the OP asked. For crypto-knowledgeable people, this
> may just be an issue of terminology (although I think an important one), but
> I think it demonstrates the ignorance of the OP and the need for Irmen's
> clarification.
>
> --
> Robert Kern

I don't mean to disrespect Paul Rubin, but p3.py comes up in every discussion
of cryptography in python on this list and, AFAICT, has yet to come under
significant cryptanalytic scrutiny. That doesn't make it a bad example in this
case, but I would caution the OP that it probably doesn't make it a good
candidate for your encryption needs.

Geremy Condra