RE: Is 80 bits enough? [Re: Advantages and disadvantages of using CB64 type of identifiers]

["Christian Huitema" <huitema@windows.microsoft.com>]

> > Everybody should be convinced that, when it comes to cryptography,
2^64
> > is actually a small number. SEND alleviates this risk by
> > cryptographically link a public key to the entire 128 bits of the
> > address. This is NOT overkill.
> 
> But is 2^80 big enough? Omitting the /48 prefix from the crypto would
> avoid the hash changing when rehoming to a different prefix.

Not really. The 16 bit subnet identifier is not very random in practice.
In many cases, the value is 0 or 1, and you get only 1 additional bit,
not 16...

-- Christian Huitema