Email security

SSL is an internet protocol for secure exchange of information between a web browser and a web server.

The document discusses various authentication techniques, including: - Password-based authentication using clear text passwords, message digests of passwords, and adding randomness with challenges. - Authentication tokens, which generate one-time passwords based on a seed value stored in the token and authentication server database. - Multifactor authentication using passwords, biometrics, and authentication tokens or smart cards. - Certificate-based authentication using digital certificates issued in a public key infrastructure for verifying user identities.

This document discusses message authentication techniques including message encryption, message authentication codes (MACs), and hash functions. It describes how each technique can be used to authenticate messages and protect against various security threats. It also covers how symmetric and asymmetric encryption can provide authentication when used with MACs or digital signatures. Specific MAC and hash functions are examined like HMAC, SHA-1, and SHA-2. X.509 is introduced as a standard for digital certificates.

The document summarizes authentication methods including Kerberos and X.509. It outlines security concerns around confidentiality and timeliness. It provides an overview of how Kerberos works, including the authentication dialogue process. It also describes X.509 certificates and certification authorities. Recommended reading and websites on authentication topics are listed.

This document provides an overview of cryptography. It defines cryptography as the science of securing messages from attacks. It discusses basic cryptography terms like plain text, cipher text, encryption, decryption, and keys. It describes symmetric key cryptography, where the same key is used for encryption and decryption, and asymmetric key cryptography, which uses different public and private keys. It also covers traditional cipher techniques like substitution and transposition ciphers. The document concludes by listing some applications of cryptography like e-commerce, secure data, and access control.

The document discusses authentication protocols and digital signatures. It describes mutual authentication protocols that allow two parties to verify each other's identities and exchange session keys. It also discusses one-way authentication protocols. The document focuses on explaining the Digital Signature Standard (DSS) and the Digital Signature Algorithm (DSA). It provides details on how DSA uses public/private key pairs to generate and verify digital signatures for authenticating messages and senders.