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Lecture

Applied Cryptography: Symmetric Integrity

In course

COM-301: Computer security and privacy

This is an introductory course to computer security and privacy. Its goal is to provide students with means to reason about security and privacy problems, and provide them with tools to confront them. ...

Description

This lecture covers symmetric cryptography algorithms for integrity, focusing on CBC-MAC. It explains how to achieve confidentiality and integrity using symmetric encryption, emphasizing the importance of Message Authentication Codes (MAC) with fixed-size keys. The lecture also delves into the concept of turning a block cipher into a MAC, specifically discussing CBC-MAC and its deterministic nature. Additionally, it explores different approaches like ENCRYPT-AND-MAC and ENCRYPT-THEN-MAC to ensure both confidentiality and integrity of data. The lecture concludes with an overview of Authenticated Encryption with Associated Data (AEAD) and modern constructions to enhance security.

Instructors (2)

Carmela González Troncoso

Edouard Bugnion

Edouard Bugnion joined EPFL in 2012, where his focus is on datacenter systems. His areas of interest include operating systems, datacenter infrastructure (systems and networking), and computer architecture. Before joining EPFL, Edouard spent 18 years in the US, where he studied at Stanford and co-founded two startups: VMware and Nuova Systems (acquired by Cisco). At VMware from 1998 until 2005, he played many roles including CTO. At Nuova/Cisco from 2005 until 2011, he helped build the core engineering team and became the VP/CTO of Ciscos Server, Access, and Virtualization Technology Group, a group that brought to market Ciscos Unified Computing System (UCS) platform for virtualized datacenters. Prof. Bugnion is a Fellow of the ACM. Together with his colleagues, he received the ACM Software System Award for VMware 1.0 in 2009. His paper Disco: Running Commodity Operating Systems on Scalable Multiprocessors" received a Best Paper Award at SOSP '97 and was entered into the ACM SIGOPS Hall of Fame Award in 2008. At EPFL, he received the OSDI 2014 Best Paper Award for his work on the IX dataplane operating system

Official source

Ontological neighbourhood

Computer engineering

Computer security: Public-key cryptography

Related concepts (32)

Encryption

In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Ideally, only authorized parties can decipher a ciphertext back to plaintext and access the original information. Encryption does not itself prevent interference but denies the intelligible content to a would-be interceptor. For technical reasons, an encryption scheme usually uses a pseudo-random encryption key generated by an algorithm.

Message authentication

In information security, message authentication or data origin authentication is a property that a message has not been modified while in transit (data integrity) and that the receiving party can verify the source of the message. Message authentication does not necessarily include the property of non-repudiation. Message authentication is typically achieved by using message authentication codes (MACs), authenticated encryption (AE), or digital signatures.

Symmetric-key algorithm

Symmetric-key algorithms are algorithms for cryptography that use the same cryptographic keys for both the encryption of plaintext and the decryption of ciphertext. The keys may be identical, or there may be a simple transformation to go between the two keys. The keys, in practice, represent a shared secret between two or more parties that can be used to maintain a private information link. The requirement that both parties have access to the secret key is one of the main drawbacks of symmetric-key encryption, in comparison to public-key encryption (also known as asymmetric-key encryption).

Disk encryption

Disk encryption is a technology which protects information by converting it into code that cannot be deciphered easily by unauthorized people or processes. Disk encryption uses disk encryption software or hardware to encrypt every bit of data that goes on a disk or disk volume. It is used to prevent unauthorized access to data storage. The expression full disk encryption (FDE) (or whole disk encryption) signifies that everything on the disk is encrypted, but the master boot record (MBR), or similar area of a bootable disk, with code that starts the operating system loading sequence, is not encrypted.

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.

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Message Authentication Codes: Formalism

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Symmetric Encryption: Physical Limits

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