alice and bob use the Hellman-diffie protocol to exchange keys and identify each other with certificates, signed by a trusted certifier (CA) and each has a private key that matches the public seducer in his certificate. eve tries to carry out a Middle-in-Men attack on alice and bob. eve can intervene at every stage in the communication between alice and bob. alice certificate will be- CERT1, and bob certificate will be- CERT2. alice signature on message m will be- SIG1(m), and bob signature on message m will be- SIG2(m). alice and bob begin the protocol by exchanging DH key and at the end hold a common key k. show if eve can succeed when the protocol continues as a follows:

  1. alice choose r1 randomaly and sends to bob < r1, CERT1 > and bob randomaly choose r2 and sends to alice < r2, CERT2 >
  2. alice and bob verify each others certificate, if the confirmations is successful alice sends SIG1(k xor r2) to bob that returns to her SIG2(k xor r1)
  3. if both signatures are correct then alice and bob encrypt the traffic between them using k.
  • 1
    $\begingroup$ What is your question? $\endgroup$ – mentallurg Jan 13 at 21:25
  • $\begingroup$ How can i show if eve can succeed acordding to the protocol? $\endgroup$ – mickey Jan 14 at 16:03

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