Re: [Drip] drip-rid-18 - CTA 2063-A encoding changes

[Robert Moskowitz <[e-mail]>]

OOPs.  One small correction.

The manufacturer can have 24 SN encodings in the Base32 approach as 2^5 
- 2^3 is 24.

On 3/29/22 08:22, Robert Moskowitz wrote:
>
>
> On 3/28/22 08:33, Robert Moskowitz wrote:
>> I am going through the changes I missed needed since decreasing the 
>> HID to 28 bits.
>>
>> Just caught that sec 4.2, CTA 2063-A needs to be reworked.  Need 4 
>> more bits, it MAY be easy, I have not done the work yet, but heads up 
>> on this one...
>
> I have time to think more on this.
>
> If I stay with the Base32 encoding, I will have to use 2 bits from the 
> 1st character in the Serial Number field.  This would work if we 
> reserve values of W,X,Y, and Z (first 3 bits 1s) for that encoding.
>
> This approach would allow manufactures to still have 7 possible 14 
> character encodings under their manufacturing code. (0 - V)
>
> I do note, now one 'error' in this section.  I say to avoid using 'Z' 
> as it is too similar to '2':
>
> "Thus, here a Base32 encoding will be used by also excluding the 
> letters Z and S (too similar to the digits 2 and 5)."
>
> Yet then I go and use it to identify HHIT encoded in 2063!
>
> "The first character after the Length Code MUST be 'Z', followed by 
> the 14 characters of the encoded HIT Suite ID and ORCHID hash."
>
> Argh.
>
> Suggestions?  Should I thus use V, W, X, and Y to encode 11100, 11101, 
> 11110, and 11111?
>
> Or I can use the Base34 encoding and then there is plenty of space in 
> 14 characters for 72 bits.
>
> Comments please.
>
> I would like to get this done by end of week, and Friday I have 3 
> grandchildren (and their parents :) ) descending on the house! Won't 
> get too much writing done then as the youngest (5 mo) uses my office 
> for her bedroom.
>
> Bob
>