Key Confirmation Sample Clauses

Key Confirmation. ‌ In authenticated protocols (AK), A will merely get the assurance of that B is the only party that is able the compute the shared key. However, in many cases it is also desirable to know if B has actually computed the shared key. Similarily, B would also want the assurance of that A has computed the shared key. This can be achieved by implementing key confirmation methods. Key confirmation ensures explicit authentication of messages. Xxxxxxxx identified in [36] a generic attack against forward secrecy on any interactive two-party key agreement protocol that only implicitly authenticates messages. In the attack, the adversary first masquerades as A and sends the inital message TA to B. B then replies with TB and completes the session with some key K. Once the session key expires at B, the adversary corrupts A, obtains the private key SA, and finally computes the agreed session key. In AKC protocols, key confirmation is usally provided by adding an extra pass and adding the MAC of the flow number, identities, and the ephemeral public keys. The MACs are computed under a shared key k j, which is different from the session key k. If the same key was used in both cases, a passive adversary would be able to learn some information about k. The adversary could then distinguish k from a key selected uniformly at random from the key space. [6] presents a provable secure AKC scheme (unified model) which many AK schemes [44, 42, 15, 58] has adopted. In this scheme, message authentication codes (MAC) are used in the Xxxxxx-Xxxxxxx scheme to provide key confirmation. MACs are computation- ally efficient and very easy to employ in protocols. Protocol (Unified Model with key confirmation) Let A and B be two entities that wish to establish a shared secret key. A first selects a ∈ Zq∗ uniformly at random and sends ga to B. On reciept, B verifies that ga ∈ [2, p − 1] and (ga)q = 1, and then in the same way selects b ∈ Z∗q and computes gb. B then computes the MAC key κ j = H1(gab) and uses κ j to compute MACκr (2, B, A, gb, ga), and sends the authenticated message to A. On reciept, A checks the validity of gb, computes κ j and verifies the authenticated message. If the MAC is ok, A sends back MACκr (3, A, B, ga, gb) to B, who then checks and verifies the message. Both parties now compute the agreed session key using a different hash function, κ = H2(gab). ga A −−− B −−−−−−−−−−−−−−−−−−− B A gb,MACκ r (2→,B,A,gb,ga) ← MACκ r (3,A,B,ga,gb) → A −−−−−−−−−−−−−−−− B UNIFIED MODEL Al...
Sample 1
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Related to Key Confirmation

  • Order Confirmation All TIPS Member Agreement purchase orders are approved daily by TIPS and sent to vendor. The vendor should confirm receipt of orders to the TIPS Member (customer) within 3 business days. • Vendor custom website for TIPS: If Vendor is hosting a custom TIPS website, updated pricing when effective. TIPS shall be notified when prices change in accordance with the award.

  • Confirmation The Company hereby agrees and assumes the duty to confirm on its behalf and on behalf of dealers or brokers who sell the Offered Shares all orders for purchase of Offered Shares accepted by the Company. Such confirmations will comply with the rules of the Commission and FINRA, and will comply with applicable laws of such other jurisdictions to the extent the Company is advised of such laws in writing by the Dealer Manager.

  • Reconfirmation (a) The employer shall reconfirm (as defined in clause 10.3.8(a)(i) above) employees to suitable positions at the merged school.

  • Daily Order Confirmation All Agreement purchase orders will be approved daily by TIPS and sent to vendor. The vendor must confirm receipt of orders to the TIPS Member (customer) within 24 business hours. • Vendor custom website for TIPS: If Vendor is hosting a custom TIPS website, then updated pricing must be posted by 1st of each month.

  • Clarification of Bidding Documents 10.1 The prospective bidder requiring any clarification of the bidding documents may notify the Employer in writing or by cable (hereinafter the term cable is deemed to include telex, email and facsimile) at the Employer’s mailing address indicated in the Bidding Data.

  • Warranty Affirmations Assurances and Certifications 3.01 Federal Assurances Performing Agency further certifies that, to the extent Federal Assurances are incorporated into the Contract under the Signature Document, the Federal Assurances have been reviewed and that Performing Agency is in compliance with each of the requirements reflected therein.

  • Required Certification Contractor must include with any request for reimbursement from the JBE a certification that Contractor is not seeking reimbursement for costs incurred to assist, promote, or deter union organizing. If Contractor incurs costs or makes expenditures to assist, promote or deter union organizing, Contractor will maintain records sufficient to show that no reimbursement from the JBE was sought for these costs, and Contractor will provide those records to the Attorney General upon request.

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