Re: [ANN] Lua 5.2.0 (work5) now available

[pj@...]

Joseph Stewart wrote:
> but what can't you do with 32-bit values that you need to do?

I wrote:
> Strong encryption ?
> In block cyphers, you need lots of XOR ops, and block sizes of
> 32 bits are inherently vulnerable but 64 bits are very tough...

Rob Kendrick wrote:
> It's difficult to see how simply doubling the number of bits
> you process at once removes an inherent vulnerability.

See:   http://en.citizendium.org/wiki/Code_book_attack

  DES and the generation of ciphers that followed it all used a 64-bit
  block size. To completely break a single key, an attacker would need
  a code book with 2^64 entries. Even to weaken it significantly takes
  a code book with 2^32 entries with the same key, 32 gigabytes of data.
  With any sensible re-keying policy, a code book attack is not a threat.
  More recent ciphers such as AES use a 128-bit block size,
  which makes code book attacks utterly impractical.

The algorithms we use down here at the consumer-level are still
64-bit-block-size, see e.g.:
  http://www.kremlinencrypt.com/algorithms.htm

Michal Kottman wrote:
> encryption in pure Lua - of course you CAN do it, but IMHO it is better
> to "leave it to the experts" and use existing cryptography libraries,
> like OpenSSL (which even come with cryptography hardware support).
> ... luacrypto (http://github.com/mkottman/luacrypto - my fork ...)

Cryptography is fun...

Regards,  Peter Billam

http://www.pjb.com.au       pj@pjb.com.au      (03) 6278 9410
"Was der Meister nicht kann,   vermöcht es der Knabe, hätt er
 ihm immer gehorcht?"   Siegfried to Mime, from Act 1 Scene 2