Provable security Sample Clauses

Provable security. A mathematical statement is an assertion about well-defined, unambiguous concepts. So whenever we want to apply the rigorous tools of mathematics to cryptography, wefirst have to decide how to model the different parties and their interactions (both honest and dishonest) that will take place in an application of our scheme. It is important to realize that a formal security proof can only support our confidence in a scheme’s practical security if the model adequately represents the context and security requirements of the application. One aspect to determine is the power of the adversary, the so-called attack model. Do we allow the adversary to choose the instance (e.g. ciphertext, iden- tity of whose signature to forge) himself, or does it have to break the scheme on any given target? Does it have unlimited computational resources, or perhaps a bounded memory? Can it access some example broken instances different from its target, to learn from? If yes, does it get to choose which example instances? The more power and freedom we grant the adversary in our attack-model, the stronger will be the claims of security that we derive. On the downside, such claims will also be harder to prove, and they might be overkill for applications where malicious parties are constrained by the context (e.g. it only pays offto inconspicuously alter the amount on yourownsavings account). As an example, consider the case of an encryption scheme. Atfirst glance, we simply desire that an adversary should not be able to decrypt a given ciphertext, i.e.figure out the corresponding encrypted plaintext. However, not being able to decrypt does not imply that the adversary is unable to extract any useful information from a ciphertext. In an encrypted voting system he might not be able to determine for which particular candidate a vote is cast, but still distinguish between votes for candidates from different political parties and thus influence the election outcome by discarding votes of a certain kind. In other contexts, an attacker might be able to influence what messages are sent over an encrypted channel and hence obtain some knowledge on the rela- tion between plaintexts and ciphertexts that can help him decrypt. A famous example comes from WWII, where the US knew from a partially decrypted ci- phertext that Japan was planning an attack against ‘AF’, and suspected this to be an encryption of ‘Midway Island’. By leaking a fake message about Midway Island, they observed the Japanese ...
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Provable security. It is very difficult to design secure cryptographic schemes. This is illustrated by the number of cryptographic schemes that have been proposed over time and in which flaws have subsequently been discovered. These flaws may be due to new attacks which were not previously known, or simply due to inadequate security analysis on the part of the scheme’s designers. It is therefore crucial to rigorously analyze a scheme for possible security flaws before it is implemented and used in practice. Traditionally, a cryptographic scheme was analyzed by constructing convincing argu- ments that a scheme was immune to the best currently known attack methods because the resources required were greater than those of any reasonable attacker. Such analysis is called heuristic analysis and schemes that survive such analysis are said to have heuristic security. However heuristic security is only a measure of security against currently known at- tacks. It gives little assurance that a scheme is in fact secure since it cannot guarantee that no previously undiscovered attack cannot compromise the scheme’s security. In 1984, Xxxxxxxxxx and Xxxxxx [61] introduced the paradigm of provable security and lead the way for far more rigorous treatments of cryptographic schemes by developing precise definitions and appropriate “models” of security for various cryptographic primi- tives. Xxxxxxxxxx, Xxxxxx and Xxxxxx [63] were the first to formalize a notion of security for digital signature schemes. They also presented a scheme that satisfied their definition under reasonable assumptions. In order to analyze cryptographic primitives, we introduce some useful terminology. An adversary or attacker of a cryptographic scheme is an entity which tries to defeat the intended security objective of the scheme. A passive adversary is one which only monitors communication channels. An active adversary is one which attempts to delete, add, or in some way modify the transmissions on a channel. When reasoning about cryptographic schemes under attack, the entities involved in such schemes, as well as the attacker(s) are modelled as interactive Turing machines, which can be seen as abstractions of modern computers. In general, these Turing machines are probabilistic, meaning that they have access to a supply of random bits. Giving a precise definition of security is an important step when analyzing the secu- rity of a cryptographic scheme. Firstly, the objectives of the scheme need to be clearly understo...
Provable security. ‌ Provable security was invented in the 1980’s by Xxxxxxxxxx and Xxxxxx [28], and origi- xxxxx applied to encryption schemes and signature schemes. A scheme is provable secure if there is a polynomial reduction proof from a known hard computational problem (such as those of Section 2.4) to an attack against the security of the scheme. Thus, if there is a polynomially bounded adversary that breaks the scheme, then the problem assumed to be hard can be solved in polynomial time. Provided that the assumption regarding the hardness of the problem is true, then no such adversary exists. The process in proving security comes in four stages [3],
Provable security. Recall DAi and DBi denote the two personal mobile devices of the user Ui, and we will now prove that the proposed protocol is secure even though one of the two mobile devices is controlled by a malicious adversary. IDt

Related to Provable security

  • E7 Security E7.1 The Authority shall be responsible for maintaining the security of the Authority’s Premises in accordance with its standard security requirements. The Contractor shall comply with all security requirements of the Authority while on the Authority’s Premises, and shall ensure that all Staff comply with such requirements.

  • Bid Security 2.1 Bid security, as a guarantee of good faith, in the form of a certified check, cashier's check, or bidder's bond, may be required to be submitted with this bid document, as indicated on the bid.

  • Valid Security Interest This Agreement creates a valid and continuing security interest (as defined in the applicable UCC) in the Sold Property in favor of the Issuer, which is prior to all other Liens, other than Permitted Liens, and is enforceable against creditors of and purchasers from the Depositor.

  • Tender Security 18.1 The Tenderer shall furnish as part of its Tender, either a Tender-Securing Declaration or a Tender Security, as specified in the TDS, in original form and, in the case of a Tender Security, in the amount and currency specified in the TDS.

  • Server Security Servers containing unencrypted PHI COUNTY discloses to 4 CONTRACTOR or CONTRACTOR creates, receives, maintains, or transmits on behalf of COUNTY 5 must have sufficient administrative, physical, and technical controls in place to protect that data, based 6 upon a risk assessment/system security review.

  • Multiple Security If (a) the Premises shall consist of one or more parcels, whether or not contiguous and whether or not located in the same county, or (b) in addition to this Mortgage, Mortgagee shall now or hereafter hold one or more additional mortgages, liens, deeds of trust or other security (directly or indirectly) for the Indebtedness upon other property in the State in which the Premises are located (whether or not such property is owned by Mortgagor or by others) or (c) both the circumstances described in clauses (a) and (b) shall be true, then to the fullest extent permitted by law, Mortgagee may, at its election, commence or consolidate in a single foreclosure action all foreclosure proceedings against all such collateral securing the Indebtedness (including the Mortgaged Property), which action may be brought or consolidated in the courts of any county in which any of such collateral is located. Mortgagor acknowledges that the right to maintain a consolidated foreclosure action is a specific inducement to Mortgagee to extend the Indebtedness, and Mortgagor expressly and irrevocably waives any objections to the commencement or consolidation of the foreclosure proceedings in a single action and any objections to the laying of venue or based on the grounds of forum non conveniens which it may now or hereafter have. Mortgagor further agrees that if Mortgagee shall be prosecuting one or more foreclosure or other proceedings against a portion of the Mortgaged Property or against any collateral other than the Mortgaged Property, which collateral directly or indirectly secures the Indebtedness, or if Mortgagee shall have obtained a judgment of foreclosure and sale or similar judgment against such collateral, then, whether or not such proceedings are being maintained or judgments were obtained in or outside the State in which the Premises are located, Mortgagee may commence or continue foreclosure proceedings and exercise its other remedies granted in this Mortgage against all or any part of the Mortgaged Property and Mortgagor waives any objections to the commencement or continuation of a foreclosure of this Mortgage or exercise of any other remedies hereunder based on such other proceedings or judgments, and waives any right to seek to dismiss, stay, remove, transfer or consolidate either any action under this Mortgage or such other proceedings on such basis. Neither the commencement nor continuation of proceedings to foreclose this Mortgage nor the exercise of any other rights hereunder nor the recovery of any judgment by Mortgagee in any such proceedings shall prejudice, limit or preclude Mortgagee's right to commence or continue one or more foreclosure or other proceedings or obtain a judgment against any other collateral (either in or outside the State in which the Premises are located) which directly or indirectly secures the Indebtedness, and Mortgagor expressly waives any objections to the commencement of, continuation of, or entry of a judgment in such other proceedings or exercise of any remedies in such proceedings based upon any action or judgment connected to this Mortgage, and Mortgagor also waives any right to seek to dismiss, stay, remove, transfer or consolidate either such other proceedings or any action under this Mortgage on such basis. It is expressly understood and agreed that to the fullest extent permitted by law, Mortgagee may, at its election, cause the sale of all collateral which is the subject of a single foreclosure action at either a single sale or at multiple sales conducted simultaneously and take such other measures as are appropriate in order to effect the agreement of the parties to dispose of and administer all collateral securing the Indebtedness (directly or indirectly) in the most economical and least time-consuming manner.

  • System Security (a) If any party hereto is given access to the other party’s computer systems or software (collectively, the “Systems”) in connection with the Services, the party given access (the “Availed Party”) shall comply with all of the other party’s system security policies, procedures and requirements that have been provided to the Availed Party in advance and in writing (collectively, “Security Regulations”), and shall not tamper with, compromise or circumvent any security or audit measures employed by such other party. The Availed Party shall access and use only those Systems of the other party for which it has been granted the right to access and use.

  • Premises Security 10.1 Security of premises and control of access.

  • Cyber Security Except as disclosed in the Registration Statement and the Prospectus, (x)(i) to the knowledge of the Company, there has been no security breach or other compromise of or relating to any information technology and computer systems, networks, hardware, software, data, or equipment owned by the Company or its subsidiaries or of any data of the Company’s, the Operating Partnership’s or the Subsidiaries’ respective customers, employees, suppliers, vendors that they maintain or that, to their knowledge, any third party maintains on their behalf (collectively, “IT Systems and Data”) that had, or would reasonably be expected to have had, individually or in the aggregate, a Material Adverse Effect, and (ii) the Company, the Operating Partnership and the Subsidiaries have not received any written notice of, and have no knowledge of any event or condition that would reasonably be expected to result in, any security breach or other compromise to their IT Systems and Data that had, or would reasonably be expected to have had, a Material Adverse Effect; (y) the Company, the Operating Partnership and the Subsidiaries are presently in compliance with all applicable laws or statutes and all applicable judgments, orders, rules and regulations of any court or arbitrator or governmental or regulatory authority, internal policies and contractual obligations relating to the protection of IT Systems and Data from a security breach or unauthorized use, access, misappropriation, modification or other compromise, except as would not, in the case of this clause (y), individually or in the aggregate, have a Material Adverse Effect; and (z) the Company, the Operating Partnership and the Subsidiaries have implemented commercially reasonable backup and disaster recovery technology.

  • User Security You agree to take every precaution to ensure the safety, security and integrity of your account and transactions when using Mobile Banking. You agree not to leave your Device unattended while logged into Mobile Banking and to log off immediately at the completion of each access by you. You agree not to provide your username, password or other access information to any unauthorized person. If you permit other persons to use your Device, login information, or other means to access Mobile Banking, you are responsible for any transactions they authorize and we will not be liable for any damages resulting to you. You agree not to use any personally identifiable information when creating shortcuts to your Account. We make no representation that any content or use of Mobile Banking is available for use in locations outside of the United States. Accessing Mobile Banking from locations outside of the United States is at your own risk.

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