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Distribution of international SessionKeys
The following steps must be executed to create Alice's SessionKey
to Bob :
- Alice asks her TA (TAAlice) for a SessionKey giving
the ID-numbers of the sender (herself) and the receiver (Bob)
- based on this information, TAAlice constructs a
stamp (ID sender + ID receiver)
- TAAlice encrypts this stamp with his PrivateKey
to generate the SessionKey from Alice to Bob (Kses)
- TAAlice sends an encrypted message to Bob's TA
(TABob) containing the SessionKey, Kses,
and the stamp
- in return, TABob sends the third and fourth blocks
which Alice needs, to forward later to Bob.
- TAAlice reconstructs Alice's PrivateKeys (direct
and inverse) : KAlice, K-1Alice
- TAAlice computes the SessionKeys (direct, inverse,
inverse complementary and inverse of inverse complementary) :
Kses, K-1ses , Kcomp
(=[11...1] XOR K-1ses) and K-1comp
- TAAlice sends 4 different encrypted blocks to Alice
:
- the first block contains the SessionKey from Alice to Bob,
Kses , encrypted with the inverse PrivateKey of Alice,
K-1Alice
- the second block contains the stamp (ID of sender + ID of
receiver) encrypted with the inverse SessionKey
- the third block contains the inverse SessionKey from Alice
to Bob, K-1ses, encrypted first with the
inverse PrivateKey of Bob, K-1Bob,
and then with the inverse PrivateKey of Alice, K-1Alice.
- the last block contains the stamp first encrypted with the
inverse of the inverse complementary SessionKey, K-1comp,
and then with the inverse SessionKey, K-1ses.
Alice and Bob use the blocks as if in a national environment :
- the first block permits Alice to reconstruct the SessionKey
whenever she sends a message to Bob. The SessionKey is NOT recorded
by Alice...
- the second block permits Alice to verify that the received
blocks are related to the SessionKey between herself and Bob.
- Alice includes the third and fourth blocks in all the messages
sent to Bob.
- the third block permits Bob to decipher all the messages sent
by Alice.
- with the last block, Bob verifies that the SessionKey was
generated as a combination of TAAlice and TABob.