RE: Secure mailing list service using OpenPGP

["森田 昌宏" <hiro@xxxxxxxxxxxxx>]

William H. Geiger III wrote:
> Unfortunately few mailers/plugins are designed to use this approach when
> singing & encrypting a message. Instead they use the sign & encrypt
> approach (one step process) which signature retention is not possible
> after decryption.

That's right.

I've read OpenPGP Message Format specification and I think that it is
logically possible to decrypt a signed&encrypted message and to extract the
message together with the signature. Is this correct?

If this is true, we can build a program to do this process and to re-encrypt
to recipients of a ML.

However, which approach should we take in? Geiger's two step approach with
prohibiting the usual one step sign&encrypt process, or my approach
described above? --hiro

--- Morita Masahiro, NTT Information Sharing Platform Laboratories.