Contracts for secure speculation Clause Samples

Contracts for secure speculation. We now define four fundamental contracts that characterize the security guarantees offered by mechanisms for secure speculation. We derive our contracts, which we fully formalize in [19], as the combination of two kinds of building blocks. 1) Building blocks for contracts: The first building block are observer modes, which govern what information a contract exposes. We define them via labels on the contract semantics. • The constant-time observer mode (ct for short) is com- monly used when reasoning about side channels in crypto- graphic algorithms. It uses labels pc A, load n, and store n to expose the value A of the program counter and the addresses n of load and store operations. The ct observer mode can be augmented with support for variable-latency instructions by additionally exposing the operands of those instructions as observations, or refined to capture adversaries that can infer addresses of memory accesses only up to the granularity of cache banks, lines, or pages [20]. We forgo both extensions for simplicity. • The architectural observer mode (arch for short) addi- tionally exposes the value v that is loaded from memory location n via the label load n = v upon each load instruction. As registers are set to zero in the initial architectural state, arch traces effectively determine the values of all registers during execution. The second building block are execution modes that charac- terize which paths need to be explored to collect observations. For processors with speculative execution, depending on the presence and effectiveness of hardware-level countermeasures, it is necessary to go beyond paths covered by the architectural semantics. • In the sequential execution mode (seq for short), programs are executed sequentially and in-order following the architec- tural semantics. • In the always-mispredict execution mode (spec for short), programs are executed sequentially, but incorrect branches run σ l1 σ l2 ln σ define the trace p (σ ) = l l
View SourceView Similar (2)
Contracts for secure speculation. Hardware-Software Contracts for Secure Speculation [10] have proposed a framework comprised of execution models and side-channel observers. This framework facilitates pro- gram analysis to identify transient-execution side channels in the combination of processor speculation and program structure [20]. We complement this work by extending from simplistic speculation models to full architectural speculation contracts to provide a foundation for reasoning about program safety using their proposed style of software analysis and vulnerability discovery.
View Source

Related to Contracts for secure speculation

  • The Contracts (i) will be sold by broker-dealers, or their registered representatives, who are registered with the Securities and Exchange Commission ("SEC") under the Securities and Exchange Act of 1934, as amended (the "1934 Act") and who are members in good standing of the National Association of Securities Dealers, Inc. (the "NASD"); (ii) will be issued and sold in compliance in all material respects with all applicable federal and state laws; and (iii) will be sold in compliance in all material respects with state insurance suitability requirements and NASD suitability guidelines.

  • Derivative Contracts (a) The Trustee shall, at the written direction of the Master Servicer, on behalf of the Trust Fund, enter into Derivative Contracts, solely for the benefit of the Class SB Certificates. Any such Derivative Contract shall constitute a fully prepaid agreement. The Master Servicer shall determine, in its sole discretion, whether any Derivative Contract conforms to the requirements of clauses (b) and (c) of this Section 4.09. Any acquisition of a Derivative Contract shall be accompanied by an appropriate amendment to this Agreement, including an Opinion of Counsel, as provided in Section 11.01, and either (i) an Opinion of Counsel to the effect that the existence of the Derivative Contract will not adversely affect the availability of the exemptive relief afforded under ERISA by U.S. Department of Labor Prohibited Transaction Exemption ("PTE") 94-29, as most recently amended, 67 Fed. Reg. 54487 (Aug. 22, 2002), to the Holders of the Class A Certificates or the Class M Certificates, as of the date the Derivative Contract is acquired by the Trustee; or (ii) the consent of each holder of a Class A Certificate or Class M Certificate to the acquisition of such Derivative Contract. All collections, proceeds and other amounts in respect of the Derivative Contracts payable by the Derivative Counterparty shall be distributed to the Class SB Certificates on the Distribution Date following receipt thereof by the Trustee. In no event shall such an instrument constitute a part of any REMIC created hereunder. In addition, in the event any such instrument is deposited, the Trust Fund shall be deemed to be divided into two separate and discrete sub-trusts. The assets of one such sub-trust shall consist of all the assets of the Trust Fund other than such instrument and the assets of the other sub-trust shall consist solely of such instrument. (b) Any Derivative Contract that provides for any payment obligation on the part of the Trust Fund must (i) be without recourse to the assets of the Trust Fund, (ii) contain a non-petition covenant provision from the Derivative Counterparty, (iii) limit payment dates thereunder to Distribution Dates and (iv) contain a provision limiting any cash payments due to the Derivative Counterparty on any day under such Derivative Contract solely to funds available therefor in the Certificate Account to make payments to the Holders of the Class SB Certificates on such Distribution Date. (c) Each Derivative Contract must (i) provide for the direct payment of any amounts by the Derivative Counterparty thereunder to the Certificate Account at least one Business Day prior to the related Distribution Date, (ii) contain an assignment of all of the Trust Fund's rights (but none of its obligations) under such Derivative Contract to the Trustee on behalf the Class SB Certificates and shall include an express consent of the Derivative Counterparty to such assignment, (iii) provide that in the event of the occurrence of an Event of Default, such Derivative Contract shall terminate upon the direction of a majority Percentage Interest of the Class SB Certificates, and (iv) prohibit the Derivative Counterparty from "setting-off" or "netting" other obligations of the Trust Fund and its Affiliates against such Derivative Counterparty's payment obligations thereunder.

  • Contracts and Leases Schedule 4.10 sets forth a true and complete list of all Leases and executory Contracts of the Company that are material to the Business, and Sellers have delivered to Buyer true and complete copies of all such Leases and Contracts, each as amended as of the Agreement Date (the “Material Contracts”). Subject to receipt of the Necessary Consents and compliance with Section 6.10 and subject to the entry of the Sale Order, and any ancillary orders of the Bankruptcy Court pertaining to assumption and assignment of Contracts (a) each of the Material Contracts is in full force and effect and constitutes a valid and binding obligation of the Company or Sellers, and, to the Knowledge of Sellers, each other party thereto, and (b) except as a result of the commencement of the Bankruptcy Cases, the Company or Sellers are not in breach or default in any material respect under any of the Material Contracts and, to the Knowledge of Sellers, the other parties to such Contracts are not in breach or default in any material respect thereunder (and in each such case, to the Knowledge of Sellers, no event exists that with the passage of time or the giving of notice would constitute such material breach or default in any material respect, result in a loss of material rights, result in the payment of any damages or penalties or result in the creation of any Liens thereunder or pursuant thereto other than Permitted Liens); except (i) for those defaults that will be cured in accordance with the Sale Order, are not required to be cured pursuant to section 365(b)(1)(A) of the Bankruptcy Code, or waived in accordance with section 365 of the Bankruptcy Code, or (ii) to the extent such breach or default would not reasonably be expected to have a Seller Material Adverse Effect. Except for filings in the Chapter 11 Cases, to Sellers’ Knowledge, none of the Material Contracts have been cancelled or otherwise terminated by the Company or Sellers, and neither the Company nor Sellers have not delivered any written notice to any counterparty to such Material Contract regarding any such cancellation or termination by the Company or Sellers.

  • Solicitations for Subcontracts, Including Procurement of Materials and Equipment In all solicitations either by competitive bidding or negotiation made by the Local Government for work to be performed under a subcontract, including procurement of materials or leases of equipment, each potential subcontractor or supplier will be notified by the Local Government of the Local Government’s obligations under this Agreement and the Acts and Regulations relative to Nondiscrimination on the grounds of race, color, or national origin.

  • Solicitations for Subcontracts, Including Procurements of Materials and Equipment In all solicitations, either by competitive bidding, or negotiation made by the contractor for work to be performed under a subcontract, including procurements of materials, or leases of equipment, each potential subcontractor or supplier will be notified by the contractor of the contractor’s obligations under this contract and the Acts and the Regulations relative to Non-discrimination on the grounds of race, color, or national origin.