A pseudorandom permutation is a mathematical construct used in cryptography and computer science, which serves to mimic the properties of a truly random permutation. A permutation is a rearrangement of elements in a specific order, and a pseudorandom permutation has two main characteristics: 1. **Deterministic**: A pseudorandom permutation is created by a specific algorithm that takes an input (the key) and generates a fixed permutation of the input data.

ESSH Client typically refers to a software application or tool used for interacting with the Extended Security Shell (ESSH), which is often a secure shell or command-line interface designed for managing and accessing remote systems securely. In some contexts, ESSH could also refer to a specific implementation of SSH (Secure Shell) with added features for enhanced security and management capabilities.

A garbled circuit is a cryptographic technique used in secure multiparty computation (SMPC) that allows one party to compute a function on private inputs while keeping those inputs hidden from the other party. The technique was introduced by Andrew Yao in the 1980s and is considered an important foundation for secure two-party computation.

Structured encryption is a cryptographic approach designed to enable efficient access and querying of encrypted data while maintaining confidentiality. It allows users to perform specific operations on encrypted data without needing to decrypt it first. This capability is particularly valuable in scenarios where sensitive data must remain encrypted, such as in cloud storage or database systems. The primary goal of structured encryption is to support certain computational tasks while preserving the data's privacy.

A **trapdoor function** is a special type of function that is easy to compute in one direction but difficult to reverse unless you have special information, known as the "trapdoor." This concept is fundamental in cryptography, particularly in the design of encryption algorithms and digital signatures. ### Characteristics of Trapdoor Functions: 1. **Easy to Compute**: Given an input \( x \), it is quick to compute \( f(x) \).

Secure Shell (SSH) is a cryptographic network protocol used to securely access and manage network devices and servers over an unsecured network. It provides a secure channel over an unsecured network by using encryption to protect the data transmitted between the client and the server. ### Key Features of SSH: 1. **Encryption**: SSH encrypts the data being transmitted, which protects it from interception and tampering.

Zero-knowledge protocols are a type of cryptographic method that allows one party (the "prover") to prove to another party (the "verifier") that they know a value or possess certain information without revealing the actual value or information itself. The term "zero-knowledge" highlights that no additional information is transmitted beyond the validity of the claim.

ALTS can refer to several things depending on the context. Here are a few possibilities: 1. **Alternative Investments**: In finance, "ALTS" is often shorthand for alternative investments, which include assets like real estate, private equity, hedge funds, commodities, and collectibles. These are typically considered outside of traditional investment categories like stocks and bonds.

Alice and Bob are fictional characters commonly used in cryptography and computer science to illustrate various concepts and scenarios. They serve as placeholders to make discussions about algorithms, protocols, and systems more relatable and easier to understand. For example, they are often used in explanations of concepts like encryption, secure communication, and key exchange protocols.

The Group Domain of Interpretation (GDI) is a concept primarily used in social sciences and related fields, often in the context of linguistics, sociology, and psychology. It refers to the shared understanding or common knowledge that individuals within a particular group possess regarding how to interpret signs, symbols, and communication within their specific social context.

"Autoroll" can refer to different concepts depending on the context, but here are a couple of common uses: 1. **In Gaming or Online Platforms**: Autoroll may refer to a feature in certain role-playing games or online games that automatically advances character attributes, skills, or progress based on predefined rules or player choices. This helps streamline gameplay by automating repetitive tasks, allowing players to focus on more engaging aspects of the game.

Delegated Path Validation is a process used in digital security systems, particularly in the context of public key infrastructures (PKIs) and certificate validation. It allows a third party to validate a digital certificate or a chain of certificates on behalf of another entity. This is particularly useful in scenarios where the entity holding the certificate may not have the necessary resources or capabilities to perform the validation itself.

Digest Access Authentication is a method used to secure web access by providing a way for users to authenticate themselves to a server without transmitting their password in clear text. It is a more secure alternative to Basic Access Authentication. Here’s how it works: 1. **Challenge-Response Mechanism**: When a client requests access to a protected resource, the server responds with a "401 Unauthorized" status code and includes a "WWW-Authenticate" header.

eCash, often stylized as "eCash," refers to a form of digital currency designed to facilitate electronic transactions over the internet. The concept originally began in the 1980s with cryptographic forms of cash, notably by David Chaum, who created digital cash systems that allowed for anonymous transactions. In a broader sense, eCash can refer to various digital currencies, including cryptocurrencies like Bitcoin, Ethereum, and stablecoins.

Encrypted Key Exchange (EKE) is a cryptographic protocol designed to securely exchange encryption keys between parties over an insecure channel. The primary goal of EKE is to ensure that the key exchange process itself is secure and resistant to various forms of attacks, including eavesdropping and man-in-the-middle attacks. ### Key Features of Encrypted Key Exchange: 1. **Confidentiality**: EKE ensures that the encryption keys exchanged during the protocol cannot be intercepted by unauthorized parties.

Enrollment over Secure Transport (EoST) is a protocol designed to facilitate secure enrollment of devices in a network, specifically in scenarios involving device management or provisioning. It enhances security during the enrollment process by ensuring that sensitive information is transmitted securely over the network. EoST typically utilizes Transport Layer Security (TLS) to provide a secure communication channel, protecting against eavesdropping and tampering.

Firefly is a key exchange protocol designed to securely establish shared keys between parties over a potentially insecure communication channel. It's part of a broader category of cryptographic protocols known as key exchange protocols, which allow two or more parties to generate a shared secret that can be used for encryption or authentication, without the need to exchange the secret itself directly. One of the notable features of Firefly is its emphasis on efficiency and computational security, especially in environments with limited resources or specific requirements for speed and bandwidth.

Hashcash is a proof-of-work system designed to limit email spam and denial-of-service attacks. It was created by Adam Back in 1997. The idea behind Hashcash is to require the sender of an email to perform a computational task, which involves calculating a hash that meets certain criteria. This process takes time and computational resources, making it more expensive for spammers to send large volumes of emails.

A list of Tor onion services refers to a compilation of websites or services that are accessible through the Tor network using ".onion" addresses. These addresses are only reachable through the Tor browser, which allows users to browse the internet anonymously. Onion services can host a variety of content, including: 1. **Forums and Communities**: Many forums exist for discussions on various topics including privacy, technology, and specific interests.

A multi-party fair exchange protocol is a cryptographic mechanism that enables multiple parties to exchange digital assets (such as digital signatures, documents, or cryptocurrencies) in a manner that ensures fairness and security. The key objectives of such a protocol include: 1. **Fairness**: No party should end up with the exchanged assets while the other parties do not. This means that the protocol ensures that either all parties receive their respective assets or none do.