Appendix:Glossary of ICT Security

This glossary of ICT security is a compilation of basic definitions from the field of privacy and security in cloud environments and cryptography. It has been compiled over the course of the WITDOM project and was conceived as a live document to be updated with new terms.

Privacy-preserving technologies related terms

• Adversarial capabilities – collection of actions (e.g., observations, computations, storage) that represent the assumed power of the adversary at the time of deploying an attack.
• Adversary – entity that deploys attacks according to her adversarial capabilities with the goal of compromising a system and gain privileged access to sensitive information.
• Anonymity – anonymity is the state of being not identifiable within a set of subjects, the anonymity set. The anonymity set is the set of all possible subjects who might cause an action.
• Anonymization – the data subject is not identifiable by all the means likely reasonably to be used either by the controller or by any other person to identify the said person.
• Anonymous communication network – network capable of hiding the relationships of communicating partner with respect to an adversary observing the communications.
• Credit risk scoring – determination of a derived numeric expression of the level or risk associated to a customer or a credit operation. It predicts whether or not a credit extended to an applicant will likely result in profit or losses for the lending institution. A credit score is based on, among other things, a person’s past credit history.
• Differential privacy – informally, the concept of differential privacy in a dataset states that any possible outcome of an analysis should be “almost” equally likely for two datasets that differ in just one element. Hence, the performed statistical analyses will not disclose significant information about one individual of the dataset.
• Data warehouse – a collection of data within an organization primarily used for reporting and analysis to support management decision-making. A Data Warehouse often contains time-varying data integrated from different information sources. The data are usually structured, organized and accessible for business users by applying tools like online analytical processing (OLAP) or Data Mining.
• Data mart – a repository of data that is designed to serve a particular community of knowledge workers and usually oriented to a specific business line or team. Generally, an organization’s data marts are subsets of the organization’s data warehouse.
• Data controller – natural or legal person, public authority, agency or any other body which alone or jointly with others determines the purposes and means of the processing of personal data.
• Data processing – any operation or set of operations which is performed upon personal data, whether or not by automatic means, such as collection, recording, organization, storage, adaptation or alteration, retrieval, consultation, use, disclosure by transmission, dissemination or otherwise making available, alignment or combination, blocking, erasure or destruction.
• Data processor - natural or legal person, public authority, agency or any other body which processes personal data on behalf of the controller.
• Data subject – the person about whom data is collected.
• Data subject’s consent – any freely given specific and informed indication of his wishes by which the data subject signifies his agreement to the processing of personal data relating to him/her.
• Electronic Genomic Record (EGR) – all the information relative to the genetic analysis of an individual, including the raw data leading to the retrieval of such information.
• Electronic Health Record (EHR) – a document maintained by each CDO the patient deals with (ANSI, 2003).
• Electronic Medical Record (EMR) – legal record created, used, and maintained by the CDO with the aim of documenting, monitoring, and managing a health care delivery within the CDO.
• End-to-end security – approach to security where data travelling between clients and servers’ end-points are uninterruptedly protected, even where untrusted intermediaries entities or communication channels are required.
• Enforcement mechanism – in the IT context, enforcement mechanisms are technical measures which guarantee that the execution and/or the outputs of a given system comply with some specific pre-established (security or privacy) policy.
• Feared Event – an event against which the system must be protected.
• Framework (privacy and security framework) – system abstraction in which tools and algorithms can be instantiated in order to provide privacy and security guarantees.
• Fraud scoring – determination of the level or risk associated to a transaction. It may provide either a pass/fail response or a quantitative score reflecting the transaction’s risk.
• Inference attack' – attack that allows the adversary to deduce the value of an attribute from the value of other attributes.
• Metadata – data holding information about data.
• Non-functional requirements – a desired quality/feature of the system (e.g., accessibility, availability, maintainability, etc.).
• Outsourced environments – refers to an arrangement by which the storage of some data and the execution of some computing tasks that would otherwise be performed in computing platforms internal to the organization, is transferred to an external entity specialized in the delivery of such tasks.
• Personal Data – any information relating to an identified or identifiable natural person, the ‘data subject’, an identifiable person is one who can be identified, directly or indirectly, in particular by reference to an identification number or to one or more factors specific to his physical, physiological, mental, economic, cultural or social identity; this term covers both objective information, but also subjective information such as opinions or assessments.
• Personally Identifiable Information (PII) – used in US privacy law: it refers to any information about an individual maintained by an agency, including (1) both any information that can be used to distinguish or trace an individual’s identity, such as name, social security number, date and place of birth, mother’s maiden name, or biometric records; and (2) any other information that is linked or linkable to an individual, such as medical, educational, financial, and employment information. It can be both sensitive or non-sensitive.
• Personal Health Information (PHI) – used in US HIPAA, it refers to any information in the medical record or designated record set that can be used to identify an individual and that was created, used, or disclosed in the course of providing a health care service such as diagnosis or treatment. PHI concerns only data associated with or derived from a healthcare service event (treatment, payment, operations, medical records).
• Privacy – the claim of individuals, groups, or institutions to determine for themselves when, how, and to what extent information about them is communicated to others. (Westin, 1967)
• Privacy policy – the declaration of an overall intention and direction, rules and commitment, as formally expressed by the data controller related to the processing of personal data in a particular setting.
• Pseudonymization – pseudonymization is the process of disguising identities. The aim of such a process is to be able to collect additional data relating to the same individual without having to know his identity. This is particularly relevant in the context of research and statistics. Pseudonymization can be done in a retraceable way by using correspondence lists for identities and their pseudonyms or by using two-way cryptography algorithms for pseudonymization. Disguising identities can also be done in a way that no re-identification is possible, e.g. by one-way cryptography, which creates in general anonymized data.
• Privacy Enhancing Technologies - PET – set of ICT measures protecting informational privacy by eliminating or minimising personal data thereby preventing unnecessary or unwanted processing of personal data, without the loss of the functionality of the information system.
• Privacy metric – means of quantification of the level of privacy achieved by one or more mechanisms with respect to a given privacy property.
• Privacy model – formalization, in technical terms, of the privacy protection that a system should provide
• Privacy preference – statement expressing users’ expectation of the degree of a privacy offered by a system.
• Privacy-and-security-by-design (PSbD) architecture -– system architecture that implicitly provides privacy and security protection.
• Privacy-preserving and security toolset Privacy-preserving and security toolset – a set of libraries comprising privacy-preserving building blocks, privacy and anonymity tools and cryptographic primitives designed for protecting data in distributed or outsourced environments.
• Privacy-preserving building block/primitive – algorithms, protocols and techniques that can be applied to enhancing the privacy of the to-be-protected signals and data, by concealing them from adversaries.
• Privacy-utility tradeoff – balance between the level of privacy achievable on a system and its subsequent loss of utility.
• Pseudoidentifier – attribute which identifies an individual when it is combined with other attributes.
• Pseudonymity – pseudonymity is the use of pseudonyms as Ids. A digital pseudonym is a bit string which is unique as ID and which can be used to authenticate the holder.
• Security – the degree of protection of an asset.
• Security requirements – OWASP defines security requirements in its quick reference guide as “a set of design and functional requirements that help ensure the software is built and deployed in a secure manner.
• Sensitive data – personal data revealing racial or ethnic origin, political opinions, religious or philosophical beliefs, trade-union membership, and the processing of data concerning health or sex life.
• Third party – any natural or legal person, public authority, agency or any other body other than the data subject, the controller, the processor and the persons who, under the direct authority of the controller or the processor, are authorized to process the data.
• Threat – the possibility that an entity (called “attacker”) exploits a vulnerability of the system.
• Toolkit – in the context of software development, a toolkit is a set of software common development tools, including, sample code, technical notes and other documentation that allows the creation of applications for a certain platform.
• Trust model – assumptions on the confidence a stakeholder in other stakeholders in the systems to preserve the privacy of sensitive data.
• Unique identifier - attribute which univocally identifies an individual within a dataset.
• Unlinkability – property that guarantees that two or more attributes regarding the same individual are no more no less related than they are given a priori knowledge.
• Unobservability – unobservability is the state of items of interest being indistinguishable from any item of interest at all (e.g., sender unobservability means that it is not noticeable whether any sender within a set sends a message).
• Untrusted environment – environments where a stakeholder cannot directly control or fully verify the underlying hardware, software or people accessing it, being vulnerable to malicious attacks. Examples of such environments are the Internet or public clouds.
• User empowerment – providing users with the means to alter aspects of the services they are consuming, In the context of data protection it implies allowing data subjects to control their own data (delete, modify or access it) and who and with what purposes they can access it.
• Validation framework and protocols – following the platform definition, a validation framework is a conceptual structure, methods and tools intended to serve as a support or guide for checking the compliance of a system with respect to a set of requirements. A validation protocol is a predefined written procedural method that will ensure a successful replication of the validation process by other validation teams.

Cryptographic terms

• Authenticated Data Structures (ADSs) – is a model for verifying operations and their results over data outsourced to untrusted sources.
• Availability – is a distributed system property. It is the proportion of the total time during which a system is capable to respond to requests. Systems with high availability systems typically achieve values of 0.99999 (or “Five Nines").
• Byzantine service – is a service which normally follows the specification but may deviate arbitrary from the specification. In other words, a service which is potentially faulty or malicious.
• Consistency, Availability, Partition tolerance (CAP) theorem– dictates that it is impossible to achieve all three properties in a distributed system. That means, in order to achieve availability and partition tolerance, one has to give up consistency.
• Certification authority (CA) – is a trusted third-party entity in a public-key infrastructure (PKI) that issues digital certificates and certifies the identity of the public-key owner.
• Consistency – is a property that defines the order and visibility of events and resulting state in a distributed system, such as distributed data stores.
• Cryptographic protocol – is a protocol to achieve a specific security objective by defining operations of cryptographic primitives. Applications of cryptographic protocols are, for example, key exchange, secret sharing and authentication.
• Data confidentiality – comprises data privacy as well as exposing information to unprivileged entities and may established by using cryptographic encryption schemes. Preservation of confidentiality of outsourced data is one of the key aspects of cloud security.
• Data integrity – refers to the correctness of data outsourced to an untrusted environment. Enforcing data integrity means to preserve consistency and accuracy of data by preventing or indicating unauthorized altering or accidental data corruption. Preservation of data integrity is one of the key aspects of cloud security.
• Digest – is also called cryptographic hash value that is the output value of a cryptographic hash function for a given input data. It is used for data integrity verification.
• Digital signature scheme – consists of three algorithms. First, a key generation algorithm that generates a private key and the corresponding public key. Second, a signing algorithm that creates a signature for a message using a private key. And last, a signature verifying algorithm that verifies the signature for a message using a public key. Without knowledge of the private key, it is not possible to generate signatures that successfully pass the verification algorithm.
• Fork-linearizability – is a consistency model which guarantees that the events seen by every client of a remote service are linearizable and if the server causes the views of two clients to diverge, they may never again see common events without exposing the server as being faulty.
• Hash chain – is a successive invocation of a cryptographic hash function. That is, the hash function is multiple times invoked on the output hash value of the previous invocation.
• Cryptographic hash functions – map arbitrary input data to a short, unique hash value. Cryptographic hash functions are one-way functions, that is, it is infeasible to compute the input data from its hash value.
• Homomorphic Encryption (HE, FHE, SHE) – malleable encryption that allows for certain operations on encrypted data without decrypting them, thanks to a group (or ring) homomorphism between the plaintext and the ciphertext. Typically, additive homomorphic encryption (only encrypted additions) is used due to the current inefficiency of Fully Homomorphic Encryption (FHE), which allows for any encrypted operation. Somewhat Homomorphic Encryption (SHE) is an efficient relaxation of FHE that allows for the execution of limited depth circuits under encryption.
• Key-value store (KVS) – is a storage system providing the abstraction of an associative array that allows storage and retrieval of values associated with unique keys. The KVS model is often used to abstract real-world cloud storage services such as Amazon S3 or Openstack Swift.
• Linearizability – is a consistency model that guarantees that at every client all events appear in the same order and preserve the global real-time ordering.
• Probabilistically checkable proofs (PCPs) – are complexity-theoretic tools that allow a client to verify that the results of a computation, or the solution of a problem, is correct. Their key feature lies in efficiency, they use a randomized verification algorithm that accesses only a part of a (very long) proof.
• Cryptographic protocol – structured procedure which makes use of one or several cryptographic primitives to comply with a security-related function. It may involve several parties, specifying the interchanged messages (interactive protocol).
• Public key Encryption with Keyword Search (PEKS)]] – cryptographic mechanism that enables to test for the presence of a determined term (keyword) in an encrypted message.
• Public key Encryption with Registered Keywork Search (PERKS)]] – variant of PEKS in which the sender must register the keyword with a receiver before using it, hence avoiding offline keyword guessing attacks.
• Remote computation – is the offloading of a computation task to another or multiple remote hosts. That is, a computationally client sends and invocation to the remote host and receives the computation result as a response.
• Trusted Platform Module (TPM) – is a secure co-processor found on modern computers that provides limited cryptographic operations and key storage. It permits to bootstrap a secure and verified computation infrastructure by informing a remote entity in cryptographically secure way about the actual hardware and software configuration of its host computer system.
• Secure processing – discipline that applies cryptographic protocols and primitives to protect and conceal data while it is processed. In the scope of processing of sensitive signals, it is usually denoted Secure Signal Processing or Signal Processing in the Encrypted Domain.
• Secure storage – set of strategies, hardware and software components and cryptographic primitives to protect data when it is neither in transit nor being processed.
• Verifiable computation (VC)– enables a client to verify the response of a remote computation with respect to a known program and known inputs.
• Vector clock – is a data structure that establishes a partial ordering of events in a distributed system and can serve to detect concurrent events.
• Wait-free – is a distributed algorithm property which guarantees that all entities in the system may progress independently of each other. That is, no entity needs to wait for another one to proceed.
• Weak fork-linearizability – is a consistency model that guarantees fork-linearizability but relaxes the guarantees for the last event at every client.
• Zero-knowledge proofs - ZKPs – protocols that allow, through interaction, to prove the validity of a statement without disclosing any additional knowledge (zero-knowledge) besides that directly derived from the proven statement.

Cloud related terms

• Access Control – selective restrictions of access put in place in order to access (web) resources.
• Authorization Server (AS) – web service within a authorization framework which checks validity of authorization tokens. The server issuing access tokens to the client after successfully authenticating the resource owner and obtaining authorization.
• Business flow – a sequence of steps/flows between flow objects (events, activities, gateways) in a work flow.
• Certificate Agency (CA) Service – Certificate Authority, issues digital certificates. These certify ownerships of public keys of services or users and are used to identify these. Within a Public Key Infrastructure model of trust relationships, it is a trusted third party, trusted by both, the subject (owner) of the certificate and the party relying uppon the certificate.
• Certificate Revocation – a process of revoking (deleting) a certificate from the chain of trust (from the CA)
• Cloud Adaptation Layer – a layer between IaaS and services that enables existing non- cloud enabled services to utilize cloud services and resources.
• Cloud API – an Application Programming Interface towards cloud resources of IaaS or PaaS. Usually implemented as RESTful service utilizing HTTP methods to perform certain methods on the cloud infrastructure.
• Cloud Brokerage Service (CBS) – a model in which a company or other entity adds value to one or more (public or private) cloud services on behalf of one or more consumers of that service via three primary roles including aggregation, integration and customization brokerage.
• Cloud deployment – a process of deploying cloud service on physical or virtual infrastructure.
• Cloud extensions – a set of tools (libraries, services) enabling an existing cloud services to perform an extended action
• Cloud Federation – interconnected cloud environments (solutions) that are seen by the users as a single entity. Cloud mechanisms are abstracted from the user who seamlessly uses different cloud providers as these would be one entity.
• Cloud infrastructures – resources (physical or virtual) used to provide cloud services to the users.
• Cloud Service Provider (CSP) – an entity providing cloud services
• ConPaaS – Contrail PaaS, it is an open source Platform-as-a-service solution developed within Contrail project. Contrail was a Cloud Federation computing project that ran from 2010-10-01 until 2014-01-31.
• ConSec – Contrail Security framework is a framework developed within Contrail project. It comprises OAuth2 implementation with dynamic CA services. These can directly be used within elastic PaaS services. It also provides Identity Provider solution enabling different cloud platforms to use the same authentication mechanisms.
• Cloud Object Store (COS) – Cloud based storage that manages discrete units of storage. Abstracts some of the lower layers of storage away from administrators and applications.
• Database as a service (DbaaS) – database managed by cloud provider. Application owners do not have to install and maintain database on their own.
• Federated Identity Management – arrangement made between multiple enterprises that lets users use same identification data to obtain access to networks of all enterprises in the group.
• ICT (Information and Communications Technology) – according to ISO “ICT includes the specification, design and development, integration and interoperability of systems, tools and applications dealing with the capture, representation, accessibility, processing, security, transfer, interchange, presentation, management, organization, storage and retrieval of information, and their related cultural, linguistic adaptability and societal aspects.
• Identity Provider (IdP) / External Identity Provider – a system that creates, maintains and manages identity information for principals (users, services, or systems) and provides principal authentication to other service providers (applications) within a federation or distributed network.
• Infrastructure as a Service IaaS – service that provides physical or virtual machines and other resources.
• IPOP (IP over P2P) Protocol– software virtual network allowing end users to create their own virtual private networks (VPNs). Packets are transferred from source directly to destination over public network without intermediate server.
• JSON Web Token (JWT) – compact URL-safe means of representing claims to be transferred between two parties. Claims are encoded as JavaScript Object Notation (JSON) object that is used as the payload of a JSON Web Signature (JWS) structure or as the plaintext of a JSON Web Encryption (JWE) structure, enabling the claims to be digitally signed or MACed and/or encrypted.
• NoSQL Database – provides a mechanism for storage and retrieval of data that is modeled in means other than the tabular relations used in relational databases. Motivations for this approach include simplicity of design, horizontal scaling and finer control over availability.
• OAuth2 – provides client applications a secure delegated access to server resources on behalf of a resource owner. It specifies a process for resource owners to authorize third-party access to their server resources without sharing their credentials.
• OpenID – decentralized protocol that allows users to be authenticated by certain cooperating websites using a third party service thus eliminating the need for users to register on every website.
• Peer-to-peer (P2P) – distributed application architecture in which peers communicate directly with each other.
• Platform as a Service (PaaS) – service that provides a platform allowing customers to develop, run and manage applications without complexity of building and maintaining the infrastructure.
• POSIX File System – part of POSIX specification that defines requirements for file systems. It mandates things like hierarchical file names, permissions and multi-user protection.
• Runtime Environment – contains state values that are accessible during program execution, as well as active entities (like environment variables) that can be interacted with during program execution.
• Software Defined Network (SDN) – an approach to networking in which control is decoupled from the physical infrastructure, allowing network administrators to support a network fabric across multi-vendor equipment.
• Software Defined Storage (SDS) – an approach to data storage in which the programming that controls storage-related tasks is decoupled from the physical storage hardware. Software that enables a software-defined storage environment can provide functionality such as deduplication, replication, thin provisioning, snapshots and backup.
• Security Vulnerability Assessment (SVA) – an inspection process that determines vulnerabilities of inspected entity. The aim of SVA is to assess the size of attack surface and try to minimize it.
• Service Level Agreement SLA – contract between service provider and customer that defines the guaranteed level of service performance.
• Service-oriented Architecture (SoA) – a design pattern in which application components provide services to other components via a communications protocol, typically over a network. The principles of service-orientation are independent of any vendor, product or technology. Service is a self-contained unit of functionality.
• Software as a Service SaaS – users are provided access to application software. Cloud providers manage infrastructure and platforms that run the applications.
• Virtual Execution Platform (VEP) – a cloud middleware software that interfaces multiple Infrastructure as a Service (IaaS) clouds and presents end-users with an interface facilitating ease of deployment and application life cycle management of distributed applications made up of several inter-networked virtual machines.
• Virtual Private Networking – extends private network across a public network. Computers send and receive data across public network as if it were directly connected to private network.
• X509 Certificate – uses X.509 public key infrastructure (PKI) standard to verify that a public key belongs to the user, computer or service identity contained within the certificate.
• eXtensible Access Control Markup Language (XACML) – a declarative access control policy language implemented in XML and a processing model describing how to evaluate access requests according to the rules defined in policies.
• XtreemFS – an object-based, distributed file system for wide area networks. It is fault tolerant and maintains POSIX file system semantics.