Re: IPG Algorith Broken!

> > Ahh... an OTP isn't unbreakable.  Its just so encredibly breakable that
> > you never know which break was the correct one ;)
> 
> Note that Schneier says "perfect", not "unbreakable".

yes,

Perfect is a better term. Strictly speaking it is because there is no 
finite unicity distance (the amount of ciphertext with which the 
cipher can theoretically be broken). So, stricly speaking, for a given 
message C and a prospective pad, P, out of a set of N pads which may 
or may not be correct:

P(P|C) = N^-1

The length of C and the amount of ciphertexts given have no effect in 
determining the key, nor is there any prospect of a know plaintext 
attack as the pad is true random and the next bits are totally 
independent of any others before them.
Of course the reason it is perfect is because there are many 
different pads which give valid decryptions and there is no way of 
knowing which one is correct.

IPG`s algorithm is definitely NOT an OTP and Don Wood is a snakeoil 
merchant.


 

  Datacomms Technologies web authoring and data security
       Paul Bradley, Paul@fatmans.demon.co.uk
  Paul@crypto.uk.eu.org, Paul@cryptography.uk.eu.org    
       Http://www.cryptography.home.ml.org/
      Email for PGP public key, ID: 5BBFAEB1
     "Don`t forget to mount a scratch monkey"

On , 25 Nov 1996 paul@fatbrain.demon.co.uk wrote:

> 
> > > Ahh... an OTP isn't unbreakable.  Its just so encredibly breakable that
> > > you never know which break was the correct one ;)
> > 
> > Note that Schneier says "perfect", not "unbreakable".
> 

More gobbledegook about nothing. Yes it is perfect and yes it is
unbreakable!

snip......
> 
> IPG`s algorithm is definitely NOT an OTP and Don Wood is a snakeoil 
> merchant.
>

Play it Paul, (or is it Sam, or fatbrain).

Never has one person said so much and said nothing,

Lead on McPuff(ery)

 
With kindest regards,

Don Wood

wichita@cyberstation.net wrote:
> On , 25 Nov 1996 paul@fatbrain.demon.co.uk wrote:
> > > > Ahh... an OTP isn't unbreakable.  Its just so encredibly breakable that
> > > > you never know which break was the correct one ;)
> > > 
> > > Note that Schneier says "perfect", not "unbreakable".
> > 
> 
> More gobbledegook about nothing. Yes it is perfect and yes it is
> unbreakable!

Don, please look at my message that analyzes your algorithm in some
detail. I think that your algorithm is far from perfect because, among
other things, your system would leave about 1 out of 7 characters
unencrypted, and also because your A(JV) are not as good as you claim 
them to be.

	- Igor.

paul@fatmans.demon.co.uk wrote:
> Perfect is a better term. Strictly speaking it is because there is no 
> finite unicity distance (the amount of ciphertext with which the 
> cipher can theoretically be broken). So, stricly speaking, for a given 
> message C and a prospective pad, P, out of a set of N pads which may 
> or may not be correct:
> 
> P(P|C) = N^-1

What does it mean?

	- Igor.

On Tue, 26 Nov 1996, Igor Chudov @ home wrote:

> paul@fatmans.demon.co.uk wrote:
> > Perfect is a better term. Strictly speaking it is because there is no 
> > finite unicity distance (the amount of ciphertext with which the 
> > cipher can theoretically be broken). So, stricly speaking, for a given 
> > message C and a prospective pad, P, out of a set of N pads which may 
> > or may not be correct:
> > 
> > P(P|C) = N^-1
> 
> What does it mean?
> 
Yes, McPuff, what does it mean. Like all of your other pabulum, it does not
mean anything that has any significance to anyone living or yet to live.
I also greatly appreciate you defining unicity distance for me, I have
always wanted to know that.

With kindest regards,

Don Wood