A hardware security module (HSM) is a physical computing device that safeguards and manages secrets (most importantly digital keys), performs encryption and decryption functions for digital signatures, strong authentication and other cryptographic functions. These modules traditionally come in the form of a plug-in card or an external device that attaches directly to a computer or network server. A hardware security module contains one or more secure cryptoprocessor chips. Design HSMs may have features that provide tamper evidence such as visible signs of tampering or logging and alerting, or tamper resistance which makes tampering difficult without making the HSM inoperable, or tamper responsiveness such as deleting keys upon tamper detection. Each module contains one or more secure cryptoprocessor chips to prevent tampering and bus probing, or a combination of chips in a module that is protected by the tamper evident, tamper resistant, or tamper responsive packaging. A vast majority of existing HSMs are designed mainly to manage secret keys. Many HSM systems have means to securely back up the keys they handle outside of the HSM. Keys may be backed up in wrapped form and stored on a computer disk or other media, or externally using a secure portable device like a smartcard or some other security token. HSMs are used for real time authorization and authentication in critical infrastructure thus are typically engineered to support standard high availability models including clustering, automated failover, and redundant field-replaceable components. A few of the HSMs available in the market have the capability to execute specially developed modules within the HSM's secure enclosure. Such an ability is useful, for example, in cases where special algorithms or business logic has to be executed in a secured and controlled environment. The modules can be developed in native C language, .NET, Java, or other programming languages. Further, upcoming next-generation HSMs can handle more complex tasks such as loading and running full operating systems and COTS software without requiring customization and reprogramming. Such unconventional designs overcome existing design and performance limitations of traditional HSMs. While providing the benefit of securing application-specific code, these execution engines protect the status of an HSM's FIPS or Common Criteria validation. Security Due to the critical role they play in securing applications and infrastructure, general purpose HSMs and/or the cryptographic modules are typically certified according to internationally recognized standards such as Common Criteria (e.g. using Protection Profile EN 419 221-5, "Cryptographic Module for