Лекция 9 - Протоколы распределения ключей
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Transcript of Лекция 9 - Протоколы распределения ключей
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ëåêöèÿ 9
Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ìèõàèë Ëåîíèäîâè÷ Áóðÿêîâ
2012 ãîä
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
I ïðîòîêîëû ïåðåäà÷è óæå ñãåíåðèðîâàííûõ êëþ÷åé;
I ïðîòîêîëû ñîâìåñòíîé âûðàáîòêè îáùèõ êëþ÷åé;
I ñõåìû ïðåäâàðèòåëüíîãî ðàñïðåäåëåíèÿ êëþ÷åé.
I îòäåëüíûå ó÷àñòíèêè
I ãðóïïû ó÷àñòíèêîâ
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
I ïðîòîêîëû ïåðåäà÷è óæå ñãåíåðèðîâàííûõ êëþ÷åé;
I ïðîòîêîëû ñîâìåñòíîé âûðàáîòêè îáùèõ êëþ÷åé;
I ñõåìû ïðåäâàðèòåëüíîãî ðàñïðåäåëåíèÿ êëþ÷åé.
I îòäåëüíûå ó÷àñòíèêè
I ãðóïïû ó÷àñòíèêîâ
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
I ïðîòîêîëû ïåðåäà÷è óæå ñãåíåðèðîâàííûõ êëþ÷åé;
I ïðîòîêîëû ñîâìåñòíîé âûðàáîòêè îáùèõ êëþ÷åé;
I ñõåìû ïðåäâàðèòåëüíîãî ðàñïðåäåëåíèÿ êëþ÷åé.
I îòäåëüíûå ó÷àñòíèêè
I ãðóïïû ó÷àñòíèêîâ
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
I ïðîòîêîëû ïåðåäà÷è óæå ñãåíåðèðîâàííûõ êëþ÷åé;
I ïðîòîêîëû ñîâìåñòíîé âûðàáîòêè îáùèõ êëþ÷åé;
I ñõåìû ïðåäâàðèòåëüíîãî ðàñïðåäåëåíèÿ êëþ÷åé.
I îòäåëüíûå ó÷àñòíèêè
I ãðóïïû ó÷àñòíèêîâ
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
I ïðîòîêîëû ïåðåäà÷è óæå ñãåíåðèðîâàííûõ êëþ÷åé;
I ïðîòîêîëû ñîâìåñòíîé âûðàáîòêè îáùèõ êëþ÷åé;
I ñõåìû ïðåäâàðèòåëüíîãî ðàñïðåäåëåíèÿ êëþ÷åé.
I îòäåëüíûå ó÷àñòíèêè
I ãðóïïû ó÷àñòíèêîâ
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
I ïðîòîêîëû ïåðåäà÷è óæå ñãåíåðèðîâàííûõ êëþ÷åé;
I ïðîòîêîëû ñîâìåñòíîé âûðàáîòêè îáùèõ êëþ÷åé;
I ñõåìû ïðåäâàðèòåëüíîãî ðàñïðåäåëåíèÿ êëþ÷åé.
I îòäåëüíûå ó÷àñòíèêè
I ãðóïïû ó÷àñòíèêîâ
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ñèììåòðè÷íîå øèôðîâàíèå. Äâóõñòîðîíèèå ïðîòîêîëû
a) A→ B : EkAB(k , t, idB), t � ìåòêà âðåìåíè, idB �
èäåíòèôèêàòîð B
b) A→ B : k + hkAB(t, idB) � èñïîëüçîâàíèå êëþ÷åâîé
õýø-ôóíêöèè
c) äîïîëíèòåëüíàÿ àóòåíòèôèêàöèÿ:
B → A: rB � ñëó÷àéíîå
A→ B : EkAB(k , rB) èëè k + hkAB(rB)
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ñèììåòðè÷íîå øèôðîâàíèå. Äâóõñòîðîíèèå ïðîòîêîëû
a) A→ B : EkAB(k , t, idB), t � ìåòêà âðåìåíè, idB �
èäåíòèôèêàòîð B
b) A→ B : k + hkAB(t, idB) � èñïîëüçîâàíèå êëþ÷åâîé
õýø-ôóíêöèè
c) äîïîëíèòåëüíàÿ àóòåíòèôèêàöèÿ:
B → A: rB � ñëó÷àéíîå
A→ B : EkAB(k , rB) èëè k + hkAB(rB)
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ñèììåòðè÷íîå øèôðîâàíèå. Äâóõñòîðîíèèå ïðîòîêîëû
a) A→ B : EkAB(k , t, idB), t � ìåòêà âðåìåíè, idB �
èäåíòèôèêàòîð B
b) A→ B : k + hkAB(t, idB) � èñïîëüçîâàíèå êëþ÷åâîé
õýø-ôóíêöèè
c) äîïîëíèòåëüíàÿ àóòåíòèôèêàöèÿ:
B → A: rB � ñëó÷àéíîå
A→ B : EkAB(k , rB) èëè k + hkAB(rB)
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ñèììåòðè÷íîå øèôðîâàíèå. Äâóõñòîðîíèèå ïðîòîêîëû
a) A→ B : EkAB(k , t, idB), t � ìåòêà âðåìåíè, idB �
èäåíòèôèêàòîð B
b) A→ B : k + hkAB(t, idB) � èñïîëüçîâàíèå êëþ÷åâîé
õýø-ôóíêöèè
c) äîïîëíèòåëüíàÿ àóòåíòèôèêàöèÿ:
B → A: rB � ñëó÷àéíîå
A→ B : EkAB(k , rB) èëè k + hkAB(rB)
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ñèììåòðè÷íîå øèôðîâàíèå. Äâóõñòîðîíèèå ïðîòîêîëû
d) B → A : rB A→ B : EkAB(kA, rA, rB , idB)B → A : EkAB(kB , rA, rB , idA)k = f (kA, kB) � âûðàáîòàííûé êëþ÷
+ âçàèìíàÿ àóòåíòèôèêàöèÿ
e) ïðîòîêîë Øàìèðà
EK � êîììóòèðóþùåå ïðåîáðàçîâàíèå:
EK1(EK2(x)) = EK2(EK1(x)) äëÿ âñåõ k1, k2, x
A→ B : EKA(k)
B → A : EKB(EKA(k))
A→ B : DKA(EKB(EKA(k)))
+ ñîîòâåòñòâóþùèå ìåòêè âðåìåíè è èäåíòèôèêàòîðû
EK (x) = xa mod p (a � îïðåäåëåòñÿ êëþ÷îì k)
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ñèììåòðè÷íîå øèôðîâàíèå. Äâóõñòîðîíèèå ïðîòîêîëû
d) B → A : rB A→ B : EkAB(kA, rA, rB , idB)B → A : EkAB(kB , rA, rB , idA)k = f (kA, kB) � âûðàáîòàííûé êëþ÷
+ âçàèìíàÿ àóòåíòèôèêàöèÿ
e) ïðîòîêîë Øàìèðà
EK � êîììóòèðóþùåå ïðåîáðàçîâàíèå:
EK1(EK2(x)) = EK2(EK1(x)) äëÿ âñåõ k1, k2, x
A→ B : EKA(k)
B → A : EKB(EKA(k))
A→ B : DKA(EKB(EKA(k)))
+ ñîîòâåòñòâóþùèå ìåòêè âðåìåíè è èäåíòèôèêàòîðû
EK (x) = xa mod p (a � îïðåäåëåòñÿ êëþ÷îì k)
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ñèììåòðè÷íîå øèôðîâàíèå. Òðåõñòîðîíèèå ïðîòîêîëû
I Èñïîëüçóþò òðåòüþ äîâåðåííóþ ñòîðîíó T (Trust)
I T õðàíèò êëþ÷è âñåõ àáîíåíòîâ
I Ïðîòîêîë Íèäõåìà�Øðåäåðà
I Ïðîòîêîë Îòâåÿ�Ðèèñà
I Ïðîòîêîë Íüþìàíà�Ñòàááëáàéíà
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ñèììåòðè÷íîå øèôðîâàíèå. Òðåõñòîðîíèèå ïðîòîêîëû
I Èñïîëüçóþò òðåòüþ äîâåðåííóþ ñòîðîíó T (Trust)
I T õðàíèò êëþ÷è âñåõ àáîíåíòîâ
I Ïðîòîêîë Íèäõåìà�Øðåäåðà
I Ïðîòîêîë Îòâåÿ�Ðèèñà
I Ïðîòîêîë Íüþìàíà�Ñòàááëáàéíà
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ñèììåòðè÷íîå øèôðîâàíèå. Òðåõñòîðîíèèå ïðîòîêîëû
I Èñïîëüçóþò òðåòüþ äîâåðåííóþ ñòîðîíó T (Trust)
I T õðàíèò êëþ÷è âñåõ àáîíåíòîâ
I Ïðîòîêîë Íèäõåìà�Øðåäåðà
I Ïðîòîêîë Îòâåÿ�Ðèèñà
I Ïðîòîêîë Íüþìàíà�Ñòàááëáàéíà
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ñèììåòðè÷íîå øèôðîâàíèå. Òðåõñòîðîíèèå ïðîòîêîëû
I Èñïîëüçóþò òðåòüþ äîâåðåííóþ ñòîðîíó T (Trust)
I T õðàíèò êëþ÷è âñåõ àáîíåíòîâ
I Ïðîòîêîë Íèäõåìà�Øðåäåðà
I Ïðîòîêîë Îòâåÿ�Ðèèñà
I Ïðîòîêîë Íüþìàíà�Ñòàááëáàéíà
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ñèììåòðè÷íîå øèôðîâàíèå. Òðåõñòîðîíèèå ïðîòîêîëû
I Èñïîëüçóþò òðåòüþ äîâåðåííóþ ñòîðîíó T (Trust)
I T õðàíèò êëþ÷è âñåõ àáîíåíòîâ
I Ïðîòîêîë Íèäõåìà�Øðåäåðà
I Ïðîòîêîë Îòâåÿ�Ðèèñà
I Ïðîòîêîë Íüþìàíà�Ñòàááëáàéíà
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ñèììåòðè÷íîå øèôðîâàíèå. Òðåõñòîðîíèèå ïðîòîêîëû
I Èñïîëüçóþò òðåòüþ äîâåðåííóþ ñòîðîíó T (Trust)
I T õðàíèò êëþ÷è âñåõ àáîíåíòîâ
I Ïðîòîêîë Íèäõåìà�Øðåäåðà
I Ïðîòîêîë Îòâåÿ�Ðèèñà
I Ïðîòîêîë Íüþìàíà�Ñòàááëáàéíà
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íèäõåìà�Øðåäåðà
1. Alice → Trent : A,B,RA
2. Trent → Alice :{RA,B,K , {K ,A}KB
}KA
3. Alice → Bob : {K ,A}KB
4. Bob → Alice : {RB}K5. Alice → Bob : {RB − 1}K
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íèäõåìà�Øðåäåðà
1. Alice → Trent : A,B,RA
2. Trent → Alice :{RA,B,K , {K ,A}KB
}KA
3. Alice → Bob : {K ,A}KB
4. Bob → Alice : {RB}K5. Alice → Bob : {RB − 1}K
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íèäõåìà�Øðåäåðà
1. Alice → Trent : A,B,RA
2. Trent → Alice :{RA,B,K , {K ,A}KB
}KA
3. Alice → Bob : {K ,A}KB
4. Bob → Alice : {RB}K5. Alice → Bob : {RB − 1}K
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íèäõåìà�Øðåäåðà
1. Alice → Trent : A,B,RA
2. Trent → Alice :{RA,B,K , {K ,A}KB
}KA
3. Alice → Bob : {K ,A}KB
4. Bob → Alice : {RB}K
5. Alice → Bob : {RB − 1}K
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íèäõåìà�Øðåäåðà
1. Alice → Trent : A,B,RA
2. Trent → Alice :{RA,B,K , {K ,A}KB
}KA
3. Alice → Bob : {K ,A}KB
4. Bob → Alice : {RB}K5. Alice → Bob : {RB − 1}K
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Îòâåÿ�Ðèèñà
1. A→ B : M,A,B, {NA,M,A,B}KAS
2. B → S : M,A,B, {NA,M,A,B}KAS, {NB ,M,A,B}KBS
3. S → B : M, {NA,KAB}KAS, {NB ,KAB}KBS
4. B → A : M, {NA,KAB}KAS
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Îòâåÿ�Ðèèñà
1. A→ B : M,A,B, {NA,M,A,B}KAS
2. B → S : M,A,B, {NA,M,A,B}KAS, {NB ,M,A,B}KBS
3. S → B : M, {NA,KAB}KAS, {NB ,KAB}KBS
4. B → A : M, {NA,KAB}KAS
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Îòâåÿ�Ðèèñà
1. A→ B : M,A,B, {NA,M,A,B}KAS
2. B → S : M,A,B, {NA,M,A,B}KAS, {NB ,M,A,B}KBS
3. S → B : M, {NA,KAB}KAS, {NB ,KAB}KBS
4. B → A : M, {NA,KAB}KAS
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Îòâåÿ�Ðèèñà
1. A→ B : M,A,B, {NA,M,A,B}KAS
2. B → S : M,A,B, {NA,M,A,B}KAS, {NB ,M,A,B}KBS
3. S → B : M, {NA,KAB}KAS, {NB ,KAB}KBS
4. B → A : M, {NA,KAB}KAS
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Îòâåÿ�Ðèèñà
1. A→ B : M,A,B, {NA,M,A,B}KAS
2. B → S : M,A,B, {NA,M,A,B}KAS, {NB ,M,A,B}KBS
3. S → B : M, {NA,KAB}KAS, {NB ,KAB}KBS
4. B → A : M, {NA,KAB}KAS
Äàííûå øàãè íå àóòåíöèôèöèðóþò B
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íüþìàíà�Ñòàááëáàéíà
1. A→ B : A,RA
2. B → T : B,RB ,EB(A,RA,TB)
3. T → A : EA(B,RA,K ,TB),EB(A,K ,TB),RB
4. A→ B : EB(A,K ,TB),EK (RB)
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íüþìàíà�Ñòàááëáàéíà
1. A→ B : A,RA
2. B → T : B,RB ,EB(A,RA,TB)
3. T → A : EA(B,RA,K ,TB),EB(A,K ,TB),RB
4. A→ B : EB(A,K ,TB),EK (RB)
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íüþìàíà�Ñòàááëáàéíà
1. A→ B : A,RA
2. B → T : B,RB ,EB(A,RA,TB)
3. T → A : EA(B,RA,K ,TB),EB(A,K ,TB),RB
4. A→ B : EB(A,K ,TB),EK (RB)
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íüþìàíà�Ñòàááëáàéíà
1. A→ B : A,RA
2. B → T : B,RB ,EB(A,RA,TB)
3. T → A : EA(B,RA,K ,TB),EB(A,K ,TB),RB
4. A→ B : EB(A,K ,TB),EK (RB)
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Àñèììåòðè÷íîå øèôðîâàíèå. Òðåõñòîðîíèèå ïðîòîêîëû
a) A→ B : EB(k , t, idA)
b) ïðîòîêîë Íèäõåìà�Øðåäåðà
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Àñèììåòðè÷íîå øèôðîâàíèå. Òðåõñòîðîíèèå ïðîòîêîëû
a) A→ B : EB(k , t, idA)
b) ïðîòîêîë Íèäõåìà�Øðåäåðà
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Àñèììåòðè÷íîå øèôðîâàíèå. Òðåõñòîðîíèèå ïðîòîêîëû
a) A→ B : EB(k , t, idA)
b) ïðîòîêîë Íèäõåìà�Øðåäåðà
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íèäõåìà�Øðåäåðà
1. Alice → Trent : A,B
2. Trent → Alice : {KB ,B}K−1T
3. Alice → Bob : T ,RA,AKB
4. Bob → Trent : B,A
5. Trent → Bob : {KA,A}K−1T
6. Bob → Alice : RB ,RAKA
7. Alice → Bob : {RB}KB
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íèäõåìà�Øðåäåðà
1. Alice → Trent : A,B
2. Trent → Alice : {KB ,B}K−1T
3. Alice → Bob : T ,RA,AKB
4. Bob → Trent : B,A
5. Trent → Bob : {KA,A}K−1T
6. Bob → Alice : RB ,RAKA
7. Alice → Bob : {RB}KB
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íèäõåìà�Øðåäåðà
1. Alice → Trent : A,B
2. Trent → Alice : {KB ,B}K−1T
3. Alice → Bob : T ,RA,AKB
4. Bob → Trent : B,A
5. Trent → Bob : {KA,A}K−1T
6. Bob → Alice : RB ,RAKA
7. Alice → Bob : {RB}KB
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íèäõåìà�Øðåäåðà
1. Alice → Trent : A,B
2. Trent → Alice : {KB ,B}K−1T
3. Alice → Bob : T ,RA,AKB
4. Bob → Trent : B,A
5. Trent → Bob : {KA,A}K−1T
6. Bob → Alice : RB ,RAKA
7. Alice → Bob : {RB}KB
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íèäõåìà�Øðåäåðà
1. Alice → Trent : A,B
2. Trent → Alice : {KB ,B}K−1T
3. Alice → Bob : T ,RA,AKB
4. Bob → Trent : B,A
5. Trent → Bob : {KA,A}K−1T
6. Bob → Alice : RB ,RAKA
7. Alice → Bob : {RB}KB
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íèäõåìà�Øðåäåðà
1. Alice → Trent : A,B
2. Trent → Alice : {KB ,B}K−1T
3. Alice → Bob : T ,RA,AKB
4. Bob → Trent : B,A
5. Trent → Bob : {KA,A}K−1T
6. Bob → Alice : RB ,RAKA
7. Alice → Bob : {RB}KB
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ïðîòîêîë Íèäõåìà�Øðåäåðà
1. Alice → Trent : A,B
2. Trent → Alice : {KB ,B}K−1T
3. Alice → Bob : T ,RA,AKB
4. Bob → Trent : B,A
5. Trent → Bob : {KA,A}K−1T
6. Bob → Alice : RB ,RAKA
7. Alice → Bob : {RB}KB
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Èñïîëüçîâàíèå ÝÖÏ
a) A→ B : EB(k , t,SA(idB , k, t)) � øèôðîâàíèå ïîäïèñàííîãî
êëþ÷à;
b) A→ B : EB(k , t),SA(idB , k , t) � øèôðîâàíèå è ïîäïèñü
êëþ÷à;
c) A→ B : t,EB(k),SA(idB , t,EB(k)) � ïîäïèñü
çàøèôðîâàííîãî ñîîáùåíèÿ, . . .
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Èñïîëüçîâàíèå ÝÖÏ
a) A→ B : EB(k , t,SA(idB , k, t)) � øèôðîâàíèå ïîäïèñàííîãî
êëþ÷à;
b) A→ B : EB(k , t),SA(idB , k , t) � øèôðîâàíèå è ïîäïèñü
êëþ÷à;
c) A→ B : t,EB(k),SA(idB , t,EB(k)) � ïîäïèñü
çàøèôðîâàííîãî ñîîáùåíèÿ, . . .
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Èñïîëüçîâàíèå ÝÖÏ
a) A→ B : EB(k , t,SA(idB , k, t)) � øèôðîâàíèå ïîäïèñàííîãî
êëþ÷à;
b) A→ B : EB(k , t), SA(idB , k , t) � øèôðîâàíèå è ïîäïèñü
êëþ÷à;
c) A→ B : t,EB(k),SA(idB , t,EB(k)) � ïîäïèñü
çàøèôðîâàííîãî ñîîáùåíèÿ, . . .
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Èñïîëüçîâàíèå ÝÖÏ
a) A→ B : EB(k , t,SA(idB , k, t)) � øèôðîâàíèå ïîäïèñàííîãî
êëþ÷à;
b) A→ B : EB(k , t), SA(idB , k , t) � øèôðîâàíèå è ïîäïèñü
êëþ÷à;
c) A→ B : t,EB(k), SA(idB , t,EB(k)) � ïîäïèñü
çàøèôðîâàííîãî ñîîáùåíèÿ, . . .
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Ñåðòèôèêàòû îòêðûòûõ êëþ÷åé
öèôðîâîé èëè áóìàæíûé äîêóìåíò, ïîäòâåðæäàþùèé
ñîîòâåòñòâèå ìåæäó îòêðûòûì êëþ÷îì è èíôîðìàöèåé,
èäåíòèôèöèðóþùåé âëàäåëüöà êëþ÷à.
CA = (idA, kA, t, ST (idA, kA, t))
idA � èäåíòèôèêàòîð A
kA � îòêðûòûé êëþ÷
t � äàòà âûäà÷è, ñðîê äåéñòâèÿ
ST (idA, kA, t) � ïîäïèñü äîâåðåííîãî öåíòðà (äëÿ íå¼ òàêæå
íóæåí îòêðûòûé êëþ÷ ⇒ öåïî÷êà ñåðòèôèêàòîâ)
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Îòêðûòîå ðàñïðåäåëåíèå êëþ÷åé.
Ïðîòîêîë Äèôôè�Õýëëìàíà
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Îòêðûòîå ðàñïðåäåëåíèå êëþ÷åé.
Ïðîòîêîë Äèôôè�Õýëëìàíà
a � îáðàçóþùèé ãðóïïû áîëüøîãî ïîðÿäêà (ïàðàìåòð
ïðîòîêîëà)
A→ B : ax , x � ñëó÷àéíîå
B → A : ay , y � ñëó÷àéíîå
k = (ax)y = (ay )x � îáùèé êëþ÷
Óÿçâèì ê àòàêå ¾÷åëîâåê ïîñåðåäèíå¿.
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Îòêðûòîå ðàñïðåäåëåíèå êëþ÷åé.
Ïðîòîêîë Äèôôè�Õýëëìàíà
a � îáðàçóþùèé ãðóïïû áîëüøîãî ïîðÿäêà (ïàðàìåòð
ïðîòîêîëà)
A→ B : ax , x � ñëó÷àéíîå
B → A : ay , y � ñëó÷àéíîå
k = (ax)y = (ay )x � îáùèé êëþ÷
Óÿçâèì ê àòàêå ¾÷åëîâåê ïîñåðåäèíå¿.
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Îòêðûòîå ðàñïðåäåëåíèå êëþ÷åé.
Ïðîòîêîë Äèôôè�Õýëëìàíà
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Îòêðûòîå ðàñïðåäåëåíèå êëþ÷åé.
Ïðîòîêîë Äèôôè�Õýëëìàíà
Âàðèàíò ïðîòîêîëà ñ èñïîëüçîâàíèåì ïîäïèñè:
1. A→ B : ax
2. B → A : ay ,Ek(SB(ax , ay )), k � îáùèé âûðàáîòàííûé êëþ÷
3. A→ B : Ek(SA(ax , ay ))
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Îòêðûòîå ðàñïðåäåëåíèå êëþ÷åé.
Ïðîòîêîë Äèôôè�Õýëëìàíà
Âàðèàíò ïðîòîêîëà ñ èñïîëüçîâàíèåì ïîäïèñè:
1. A→ B : ax
2. B → A : ay ,Ek(SB(ax , ay )), k � îáùèé âûðàáîòàííûé êëþ÷
3. A→ B : Ek(SA(ax , ay ))
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Îòêðûòîå ðàñïðåäåëåíèå êëþ÷åé.
Ïðîòîêîë Äèôôè�Õýëëìàíà
Âàðèàíò ïðîòîêîëà ñ èñïîëüçîâàíèåì ïîäïèñè:
1. A→ B : ax
2. B → A : ay ,Ek(SB(ax , ay )), k � îáùèé âûðàáîòàííûé êëþ÷
3. A→ B : Ek(SA(ax , ay ))
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Îòêðûòîå ðàñïðåäåëåíèå êëþ÷åé.
Ïðîòîêîë Äèôôè�Õýëëìàíà
Âàðèàíò ïðîòîêîëà ñ èñïîëüçîâàíèåì ïîäïèñè:
1. A→ B : ax
2. B → A : ay ,Ek(SB(ax , ay )), k � îáùèé âûðàáîòàííûé êëþ÷
3. A→ B : Ek(SA(ax , ay ))
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Îòêðûòîå ðàñïðåäåëåíèå êëþ÷åé.
Ïðîòîêîë Ìàöóìîòî�Òàêàøèìè�Èìàè
ZA = apA, ZB = apB � îòêðûòûå êëþ÷è
A→ B : ax
B → A : ay
k = (ay )pAZ xB = (ax)pBZ y
A = axpB+ypA � îáùèé êëþ÷
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Îòêðûòîå ðàñïðåäåëåíèå êëþ÷åé.
Ïðîòîêîë Ìàöóìîòî�Òàêàøèìè�Èìàè
ZA = apA, ZB = apB � îòêðûòûå êëþ÷è
A→ B : ax
B → A : ay
k = (ay )pAZ xB = (ax)pBZ y
A = axpB+ypA � îáùèé êëþ÷
Ëåêöèÿ 9 Ïðîòîêîëû ðàñïðåäåëåíèÿ êëþ÷åé
Îòêðûòîå ðàñïðåäåëåíèå êëþ÷åé.
Ïðîòîêîë Ìàöóìîòî�Òàêàøèìè�Èìàè
ZA = apA, ZB = apB � îòêðûòûå êëþ÷è
A→ B : ax
B → A : ay
k = (ay )pAZ xB = (ax)pBZ y
A = axpB+ypA � îáùèé êëþ÷