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150 lines
3.8 KiB
150 lines
3.8 KiB
\documentclass{beamer}
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\usepackage{graphicx}
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\usetheme{Madrid}
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\title[Crypto Basics]{Introduction to Trusted Computing: \\ Crypto and Security Basics}
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\author{Ariel Segall\\ ariels@alum.mit.edu}
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\date{Day 1\\ \bigskip Approved for Public Release: 12-2749. \\Distribution unlimited}
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\begin{document}
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\begin{frame}
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es
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\maketitle
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\end{frame}
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\begin{frame}{License}
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All materials are licensed under a Creative Commons ``Share Alike'' license.
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\begin{itemize}
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\item http://creativecommons.org/licenses/by-sa/3.0
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\end{itemize}
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\includegraphics[width=4in]{creativecommons.png}
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\end{frame}
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\begin{frame}{The Lightning Review}
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Goal: quickly familiarize you with the following concepts, or refresh your memory
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\begin{itemize}
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\item Core security principles
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\item Nonce
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\item Cryptographic keys (symmetric and asymmetric)
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\item Hashes
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\item Common attack terms
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\end{itemize}
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Confused? Ask questions early and often!
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\end{frame}
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\begin{frame}{What do we mean by secure?}
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Three basic concepts:
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\begin{itemize}
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\item Confidentiality (Secrecy)
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\item Integrity
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\item Availability
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\end{itemize}
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Trusted computing focuses on the first two.
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\end{frame}
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\begin{frame}{Freshness and Nonces}
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\begin{itemize}
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\item We often want to be sure that data is \textit{fresh}, or recent.
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\begin{itemize}
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\item Am I actually talking to you now, or is this a recording?
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\end{itemize}
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\item Our primary tool: \textit{nonces}
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\item Nonce: \textit{freshly generated} random number
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\begin{itemize}
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\item Must be unpredictable!
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\end{itemize}
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\item Nonce generator knows any message containing their nonce was created after the nonce
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\item Allows locally verifiable confirmation that remote activity current
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\begin{itemize}
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\item Timestamps aren't verifiable! Too predictable.
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\end{itemize}
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\end{itemize}
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\end{frame}
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\begin{frame}{Cryptographic Keys}
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Two main types:
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\begin{itemize}
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\item Symmetric keys
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\item Asymmetric keys
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\begin{itemize}
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\item aka ``public keys'', ``public-private key pairs''
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\end{itemize}
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\end{itemize}
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\end{frame}
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\begin{frame}{Symmetric Key Cryptography}
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\begin{itemize}
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\item Same key used for all operations: encryption vs. decryption, signing vs. verifying
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\item Usually very fast, good for bulk operations
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\item Big disadvantage: key distribution
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\item Not a primary topic for today
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\end{itemize}
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\end{frame}
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\begin{frame}{Public Key Cryptographic (Asymmetric)}
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\begin{itemize}
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\item Keys come in pairs: one public, one private
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\begin{itemize}
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\item Public key is just that: no security risk from world knowing
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\item Private key must be kept secret.
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\end{itemize}
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\item Private key used for decryption, signing
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\item Public key used for encryption, verification
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\item Great for proofs of identity
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\item Slow to use; not very good for bulk operations
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\item RSA: most common public key algorithm in use now
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\end{itemize}
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\end{frame}
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\begin{frame}{Hashes}
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\begin{itemize}
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\item Cryptographic hash: one-way function from arbitrary data to fixed length
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\item Critical hash properties:
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\begin{itemize}
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\item Easy to calculate
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\item Infeasible to reconstruct data from hash
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\item Infeasible to find collisions (different data, same hash)
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\item Infeasible to modify data without changing hash
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\end{itemize}
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\item SHA1: hash algorithm primarily referred to in this class
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\begin{itemize}
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\item More recent algorithms exist; not widely supported in hardware yet
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\end{itemize}
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\end{itemize}
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\end{frame}
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\begin{frame}{Common Attack Terms}
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\begin{description}
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\item [Denial of Service (DoS)] Attack where adversary causes service
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to be unavailable, temporarily or permanently. DoSes can also happen by accident.
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\item [Man in the Middle (MitM)] Attack where adversary fowards messages between parties, potentially modifying them, to deceive one or both parties or to reveal supposedly secret information.
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\end{description}
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\end{frame}
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\begin{frame}{Questions?}
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\end{frame}
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\end{document}
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