Cryptography – Security Levels
This post is part of the Computer Security – Cryptography posts series.
Security Level 1
Security Level 1 offers the lowest level of assurance. Primary security necessities are stipulated for a cryptographic module (for instance, at least one Approved security function must be utilized). No particular physical security mechanisms are demanded in a Security Level 1 cryptographic module beyond the primary necessity for production-grade parts.
Security Level 1 permits the software parts of a cryptographic module to be accomplished on a general purpose calculating system utilizing an unevaluated OS. Such implementations may be appropriate for security applications where controls, such as physical security, network security, and administrative procedures are offered outside of the module.
The implementation of Level 1 cryptographic software may be more cost-effective than corresponding hardware-based mechanisms, enabling organizations to select from alternative cryptographic solutions to meet lower-level security necessities.
Security Level 2
Security Level 2 enhances the physical security mechanisms of a Security Level 1 cryptographic module by adding the necessity for tamper-evidence, which includes the utilize of tamper-evident coatings or seals, or for pick-resistant locks on removable covers or doors of the module.
Tamper-evident coatings or seals are placed on a cryptographic module so that the coating or seal must be broken to attain physical access to the Critical Security Parameters within the module.
Tamper-evident seals or pick-resistant locks are placed on covers or doors to protect against unauthorized physical access.
Security Level 2 demands role-based authentication in which a cryptographic module authenticates the authorization of an operator to assume a specific role and perform a corresponding set of services.
Security Level 2 permits the software parts of a cryptographic module to be performed on a general purpose calculating system utilizing an OS that
- offers discretionary access controls that protect against unauthorized execution, modification, and reading of cryptographic software, and
- offers audit mechanisms to record alterations, accesses, deletions, and additions of cryptographic information and sensitive security parameters.
An OS applying these controls offers a level of trust (logical protection) so that cryptographic modules performing on general purpose calculating platforms are corresponding to cryptographic modules implemented utilizing dedicated hardware systems.
Security Level 3
In plus to the tamper-evident physical security mechanisms necessitated at Security Level 2, Security Level 3 attempts to forbid the unauthorized access to Critical Security Parameters held within the cryptographic module.
Physical security mechanisms needed at Security Level 3 are designated to have a high probability of detecting and responding to attempts that offer direct physical access, and utilize of or modification of the cryptographic module. The physical security mechanisms may include the utilization of strong enclosures and tamper detection and response circuitry that zeroizes all plaintext Critical Security Parameters when the removable covers or doors of the cryptographic module are opened.
Security Level 3 demands identity-based authentication mechanisms, enhancing the security provided by the role-based authentication mechanisms specified for Security Level 2. A cryptographic module authenticates the identity of an operator and verifies that the identified operator is authorized to assume a specific role and perform a corresponding set of services.
Security Level 3 requires that the entry or output of Critical Security Parameters (including the entry or output of Critical Security Parameters using split knowledge procedures) be executed utilizing ports that are physically separated from other ports, or interfaces that are logically separated utilizing a trusted channel from other interfaces. Critical Security Parameters may either be entered into or output from the cryptographic module in encrypted form or using a split knowledge procedure.
Security Level 3 demands mechanisms to protect Critical Security Parameters against timing analysis attacks.If a module may operate in both an Approved and non-Approved mode, Security Level 3 requires an indication when the module is in the Approved mode.
Security Level 3 permits the software components of a cryptographic module to be executed on a general purpose calculating system utilizing an OS that
- forbids operators in the user role from modifying cryptographic module software, system Sensitive Security Parameters (SSPs), and audit data stored in the operational environment of the module,
- communicates all Sensitive Security Parameters, authentication data, control inputs, and status outputs via a trusted channel, and
- audits the operation of the trusted channel.
The implementation of a trusted channel protects plaintext Critical Security Parameters and the software of the cryptographic module from other untrusted software that may be performing on the system and from spoofing by a remote system.
Level 3 modules necessitate extra life-cycle assurances, such as automated configuration management, detailed design, low-level testing, and operator authentication using vendor-provided authentication data.
Security Level 4
At Security Level 4, the physical security mechanisms supply a complete envelope of protection around the cryptographic module with the intent of detecting and responding to all unauthorized attempts at physical access. Penetration of the cryptographic module enclosure from any direction has a high probability of being detected, resulting in the immediate zeroization of all plaintext Critical Security Parameters . Security
Level 4 cryptographic modules are effective for operation in physically unprotected environments.
Security Level 4 introduces the two-factor authentication demand for operator authentication. This demands two of the succeeding three attributes:
- something known, such as a secret password,
- something possessed, such as a physical key or token,
- a physical property, such as a biometric.
Security Level 4 also protects a cryptographic module against a security compromise attributable environmental circumstances or fluctuations outside of the module’s normal operating ranges for voltage and temperature.
A cryptographic module is necessitated to either include special environmental protection characteristics projected to detect fluctuations and zeroize Critical Security Parameters , or to undergo rigorous environmental failure testing to provide a reasonable assurance that the module won’t be affected by fluctuations outside of the normal operating range in a manner that can compromise the security of the module.
Level 4 modules necessitate the protection of Critical Security Parameters against simple power analysis and differential power analysis attacks.
Level 4 modules that contain software must offer for the encryption and authentication of Critical Security Parameters and integrity test code when the module isn’t used. This provides for the strong protection of Critical Security Parameters from unauthorized disclosure and alteration when the module is inactive.
Security Level 4 permits the software parts of a cryptographic module to be performed on a general purpose calculating system utilizing an OS that offers for the auditing of all operator accesses to audit information, all requests to utilize authentication information management mechanisms, all utilize of security-relevant crypto officer functions, and all requests to access authentication information associated with the cryptographic module.
The design of a Level 4 module is verified by an informal proof of correspondence between both pre- and post-conditions and the functional specification.
Security Level 5
Security Level 5 offers the highest level of security in the standard. This level includes all the appropriate security features of the lower levels, also as extended features.
Level 5 modules that contain software must offer for the encryption and authentication of all retained Sensitive Security Parameters and integrity test code when the module isn’t used. This provides strong cryptographic protection to detect and prevent the disclosure and modification of Public Security Parameters (PSPs) as well as Critical Security Parameters when the module is inactive.
Level 5 modules have environmental failure protection mechanisms that protect the module from fluctuations in temperature and voltage. Level 5 modules are opaque to non-visual radiation examination and the tamper detection and zeroization circuitry is protected against disablement. When zeroization is needed,Public Security Parameters as well as Critical Security Parameters are zeroized.
At Level 5, Critical Security Parameters are protected from electromagnetic emanation attacks.
The design of a Level 5 module is verified by a formal model and informal proof of correspondence between the formal model and the functional specification.
Cryptographic module
10 Responses to “Cryptography – Security Levels”
What is MAC in cryptography ?
A MACs is an algorithm an is used to protect the integrity of transmitted or stored
data ( and to provide evidence regarding the origin of data .
What are the pair of keys for a digital signature algorithm ?
1) a private signing key, which defines the signature transformation and
which is known only to the key pair owner;
2) a public verification key, which defines the verification transformation
and which can be made available to any party needing to verify signatures
originating from the owner of the private key
What is the standard for Secure E-Commerce ?
The standard is Secure Sockets Layer(SSL) and believe it or not but is almost ten years old.
The first implementations of SSL were limited to 40-bit encryption but now cand handle 128-bit encryption.
What equipment do I need to set up an e-commerce site using SSL ?
A server to use as your Web server/e-commerce site
A redundant server to mirror your Web site
A firewall to protect your internal network
A key server/certificate server to issue keys and Digital Certificates that SSL needs to operate
A database server to hold all the data for the Web server
A back-up device/server to store data from the database
Cryptographic accelerator cards
What Encryption Products do you recommend ?
This a list of some very useful products that you can try for free or for very little money:
PGP
GAIM
madeSafe Vault
Password Safe
Kerberos
OpenSSL and Apache SSL
SafeHouse
WebCrypt
Privacy Master
Advanced Encryption Package
interesting post
a very good article about Cryptography – Security Levels