CDR: RE: RE: Re: Permutations in DES

[Trei, Peter]

> ----------
> From: 	Trei, Peter
> Reply To: 	Trei, Peter
> Sent: 	Thursday, September 07, 2000 10:06 AM
> To: 	cypherpunks at einstein.ssz.com; 'juzam'
> Subject: 	CDR: RE: Re: Permutations in DES
> 
> My understanding is that the initial permutation, (which essentially
> writes the 64 bits of key in a 8 x 8 block by column and row,
                          ^ replace 'key' with 'data'. mea culpa  -pt
> then reads it out by row and column) was included to simplify
> early DES chip hardware. It has no impact on the security of 
> the algorithm. If you know what you are doing, it does not effect 
> key agility in software implementations. 
> 
> Peter Trei
>