Lecture

Cryptography Basics

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Description

This lecture covers the fundamentals of cryptography, including symmetric and public-key systems, confidentiality, integrity, error detection, error correction, hash functions, signatures, and authentication. It explains how encryption works, the importance of keys, encoding vs. encryption, data integrity, error detection schemes, and digital signatures. The instructor also discusses password storage, checksums, and the concept of digital seals. Furthermore, the lecture delves into cryptographic hash functions, password security, ensuring data integrity, and the process of authentication. It concludes with an overview of digital signatures and the significance of non-repudiation in secure communication.

Official source

Ontological neighbourhood

Computer engineering

Computer security: Public-key cryptography

Related concepts (32)

Key (cryptography)

A key in cryptography is a piece of information, usually a string of numbers or letters that are stored in a file, which, when processed through a cryptographic algorithm, can encode or decode cryptographic data. Based on the used method, the key can be different sizes and varieties, but in all cases, the strength of the encryption relies on the security of the key being maintained. A key's security strength is dependent on its algorithm, the size of the key, the generation of the key, and the process of key exchange.

Multi-factor authentication

Multi-factor authentication (MFA; two-factor authentication, or 2FA, along with similar terms) is an electronic authentication method in which a user is granted access to a website or application only after successfully presenting two or more pieces of evidence (or factors) to an authentication mechanism. MFA protects personal data—which may include personal identification or financial assets—from being accessed by an unauthorized third party that may have been able to discover, for example, a single password.

Authentication

Authentication (from αὐθεντικός authentikos, "real, genuine", from αὐθέντης authentes, "author") is the act of proving an assertion, such as the identity of a computer system user. In contrast with identification, the act of indicating a person or thing's identity, authentication is the process of verifying that identity. It might involve validating personal identity documents, verifying the authenticity of a website with a digital certificate, determining the age of an artifact by carbon dating, or ensuring that a product or document is not counterfeit.

Cryptography

Cryptography, or cryptology (from κρυπτός "hidden, secret"; and γράφειν graphein, "to write", or -λογία -logia, "study", respectively), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, information security, electrical engineering, digital signal processing, physics, and others.

Mutual authentication

Mutual authentication or two-way authentication (not to be confused with two-factor authentication) refers to two parties authenticating each other at the same time in an authentication protocol. It is a default mode of authentication in some protocols (IKE, SSH) and optional in others (TLS). Mutual authentication is a desired characteristic in verification schemes that transmit sensitive data, in order to ensure data security. Mutual authentication can be accomplished with two types of credentials: usernames and passwords, and public key certificates.

Related lectures (64)

Public-Key Cryptography: Key Exchange and Signatures

Explores public-key cryptography, key exchange, and digital signatures, discussing practical applications and security mechanisms.

Cryptography basics: Quantum Systems

Covers the basics of cryptography, encryption, decryption, error detection, and the impact of quantum computing.

Cryptographic Security Fundamentals

Covers cryptographic security fundamentals, including collision search algorithms, public-key cryptography, and risks of underestimating collision attacks.

Cryptography: Fundamentals and Applications

Introduces the fundamentals of cryptography, covering symmetric and asymmetric encryption, hash functions, key infrastructure, and data integrity.

Conditional Access II