Encryption keys in the OpenPGP spec

[James P. Howard, II]

I am trying to understand the differences in key types and looking at
encryption keys in particular.  RFC 4880 has this to say on the matter
of key flags:

       0x04 - This key may be used to encrypt communications.

       0x08 - This key may be used to encrypt storage.

So, my first question is why is there a distinction between the two
types of encryption?

Also, looking in GnuPG 1.4.9, I see this in g10/keygen.c:

    if (use & PUBKEY_USAGE_ENC)
        buf[0] |= 0x04 | 0x08;

Which suggests, quite strongly, that the distinction is irrelevant.  Why
GnuPG ignore the different encryption key types?

Thank you, James

-- 
James P. Howard, II, MPA
jh at jameshoward.us

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