The Call of the Open Sidewalk

From a place slightly to the side of the more popular path

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pgpfan:mdc

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pgpfan:mdc [2022/07/22 15:50] – Readers might not know what a hash is. b.walzerpgpfan:mdc [2022/12/27 22:00] – We have a theoretical cryptography discussion now. b.walzer
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 I once worked for a company that had a strange and intriguing dilemma. They had a popular Product. Marketing determined that the popularity was due to the fact that the Product lasted significantly longer than competing products. No one in the company had the faintest idea why that was the case. The design did not differ in any obvious way from the design used by the competition. While I was there, an engineering project was initiated with the hope of understanding why the Product was better. I left the company before any definite result. For all I know the mystery still remains. I once worked for a company that had a strange and intriguing dilemma. They had a popular Product. Marketing determined that the popularity was due to the fact that the Product lasted significantly longer than competing products. No one in the company had the faintest idea why that was the case. The design did not differ in any obvious way from the design used by the competition. While I was there, an engineering project was initiated with the hope of understanding why the Product was better. I left the company before any definite result. For all I know the mystery still remains.
  
-The situation with the OpenPGP modification detection code (MDC) very much reminds me of the story of the Product. Legend has it that the MDC was created as a kind of an afterthought. It works very well but it is not obvious why it does. I have never seen an inclusive explanation. Here I will attempt to produce such an explanation.+The situation with the OpenPGP modification detection code (MDC) very much reminds me of the story of the Product. Legend has it that the MDC was created as a kind of an afterthought((Since I first wrote this, I have come to believe that this is //just// a legend. The principles that make the MDC work were known at the time of its design. See the [[pgpfan:intptxt]] article for the details.)). It works very well but it is not obvious why it does. I have never seen an inclusive explanation. Here I will attempt to produce such an explanation.
  
 When OpenPGP is used for something like email, the messages are authenticated directly with a signature. So the MDC is not relevant in the most common use case. So the MDC is not that important. It would still simplify things and eliminate much pointless discussion if the MDC could in fact be shown as strong. It would eliminate having to go through the more obscure uses of OpenPGP to determine how applicable the MDC was to each. When OpenPGP is used for something like email, the messages are authenticated directly with a signature. So the MDC is not relevant in the most common use case. So the MDC is not that important. It would still simplify things and eliminate much pointless discussion if the MDC could in fact be shown as strong. It would eliminate having to go through the more obscure uses of OpenPGP to determine how applicable the MDC was to each.
pgpfan/mdc.txt · Last modified: 2023/12/11 13:30 by b.walzer