Cold Boot Attacks on Encryption Keys
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Shorten Device Boot Time for Automotive IVI and Navigation Systems
Shorten Device Boot Time for Automotive IVI and Navigation Systems Jim Huang ( 黃敬群 ) <[email protected]> Dr. Shi-wu Lo <[email protected]> May 28, 2013 / Automotive Linux Summit (Spring) Rights to copy © Copyright 2013 0xlab http://0xlab.org/ [email protected] Attribution – ShareAlike 3.0 Corrections, suggestions, contributions and translations You are free are welcome! to copy, distribute, display, and perform the work to make derivative works Latest update: May 28, 2013 to make commercial use of the work Under the following conditions Attribution. You must give the original author credit. Share Alike. If you alter, transform, or build upon this work, you may distribute the resulting work only under a license identical to this one. For any reuse or distribution, you must make clear to others the license terms of this work. Any of these conditions can be waived if you get permission from the copyright holder. Your fair use and other rights are in no way affected by the above. License text: http://creativecommons.org/licenses/by-sa/3.0/legalcode Goal of This Presentation • Propose a practical approach of the mixture of ARM hibernation (suspend to disk) and Linux user-space checkpointing – to shorten device boot time • An intrusive technique for Android/Linux – minimal init script and root file system changes are required • Boot time is one of the key factors for Automotive IVI – mentioned by “Linux Powered Clusters” and “Silver Bullet of Virtualization (Pitfalls, Challenges and Concerns) Continued” at ALS 2013 – highlighted by “Boot Time Optimizations” at ALS 2012 About this presentation • joint development efforts of the following entities – 0xlab team - http://0xlab.org/ – OSLab, National Chung Cheng University of Taiwan, led by Dr. -
Basic Cryptography
Basic cryptography • How cryptography works... • Symmetric cryptography... • Public key cryptography... • Online Resources... • Printed Resources... I VP R 1 © Copyright 2002-2007 Haim Levkowitz How cryptography works • Plaintext • Ciphertext • Cryptographic algorithm • Key Decryption Key Algorithm Plaintext Ciphertext Encryption I VP R 2 © Copyright 2002-2007 Haim Levkowitz Simple cryptosystem ... ! ABCDEFGHIJKLMNOPQRSTUVWXYZ ! DEFGHIJKLMNOPQRSTUVWXYZABC • Caesar Cipher • Simple substitution cipher • ROT-13 • rotate by half the alphabet • A => N B => O I VP R 3 © Copyright 2002-2007 Haim Levkowitz Keys cryptosystems … • keys and keyspace ... • secret-key and public-key ... • key management ... • strength of key systems ... I VP R 4 © Copyright 2002-2007 Haim Levkowitz Keys and keyspace … • ROT: key is N • Brute force: 25 values of N • IDEA (international data encryption algorithm) in PGP: 2128 numeric keys • 1 billion keys / sec ==> >10,781,000,000,000,000,000,000 years I VP R 5 © Copyright 2002-2007 Haim Levkowitz Symmetric cryptography • DES • Triple DES, DESX, GDES, RDES • RC2, RC4, RC5 • IDEA Key • Blowfish Plaintext Encryption Ciphertext Decryption Plaintext Sender Recipient I VP R 6 © Copyright 2002-2007 Haim Levkowitz DES • Data Encryption Standard • US NIST (‘70s) • 56-bit key • Good then • Not enough now (cracked June 1997) • Discrete blocks of 64 bits • Often w/ CBC (cipherblock chaining) • Each blocks encr. depends on contents of previous => detect missing block I VP R 7 © Copyright 2002-2007 Haim Levkowitz Triple DES, DESX, -
Operating System Boot from Fully Encrypted Device
Masaryk University Faculty of Informatics Operating system boot from fully encrypted device Bachelor’s Thesis Daniel Chromik Brno, Fall 2016 Replace this page with a copy of the official signed thesis assignment and the copy of the Statement of an Author. Declaration Hereby I declare that this paper is my original authorial work, which I have worked out by my own. All sources, references and literature used or excerpted during elaboration of this work are properly cited and listed in complete reference to the due source. Daniel Chromik Advisor: ing. Milan Brož i Acknowledgement I would like to thank my advisor, Ing. Milan Brož, for his guidance and his patience of a saint. Another round of thanks I would like to send towards my family and friends for their support. ii Abstract The goal of this work is description of existing solutions for boot- ing Linux and Windows from fully encrypted devices with Secure Boot. Before that, though, early boot process and bootloaders are de- scribed. A simple Linux distribution is then set up to boot from a fully encrypted device. And lastly, existing Windows encryption solutions are described. iii Keywords boot process, Linux, Windows, disk encryption, GRUB 2, LUKS iv Contents 1 Introduction ............................1 1.1 Thesis goals ..........................1 1.2 Thesis structure ........................2 2 Boot Process Description ....................3 2.1 Early Boot Process ......................3 2.2 Firmware interfaces ......................4 2.2.1 BIOS – Basic Input/Output System . .4 2.2.2 UEFI – Unified Extended Firmware Interface .5 2.3 Partitioning tables ......................5 2.3.1 MBR – Master Boot Record . -
Mobiceal: Towards Secure and Practical Plausibly Deniable Encryption on Mobile Devices
2018 48th Annual IEEE/IFIP International Conference on Dependable Systems and Networks MobiCeal: Towards Secure and Practical Plausibly Deniable Encryption on Mobile Devices Bing Chang∗, Fengwei Zhang†, Bo Chen‡, Yingjiu Li∗, Wen-Tao Zhu§, Yangguang Tian∗, Zhan Wang¶ and Albert Ching ∗School of Information Systems, Singapore Management University, {bingchang, yjli, ygtian}@smu.edu.sg †Department of Computer Science, Wayne State University, [email protected] ‡Department of Computer Science, Michigan Technological University, [email protected] §Data Assurance and Communications Security Research Center, Chinese Academy of Sciences, [email protected] ¶RealTime Invent, Inc. i-Sprint Innovations Abstract—We introduce MobiCeal, the first practical Plausibly searched and copied when he was crossing a border, and he Deniable Encryption (PDE) system for mobile devices that can was inspected for seven times during five years [26]. defend against strong coercive multi-snapshot adversaries, who The existing PDE systems on mobile devices [21], [34], may examine the storage medium of a user’s mobile device at different points of time and force the user to decrypt data. [35], [43], [27], [20] are not resilient against such multi- MobiCeal relies on “dummy write” to obfuscate the differences snapshot attacks since they hide sensitive data in the ran- between multiple snapshots of storage medium due to existence domness initially filled across the entire disk. By comparing of hidden data. By incorporating PDE in block layer, MobiCeal storage snapshots at different points of time, a multi-snapshot supports a broad deployment of any block-based file systems on adversary may detect any unaccountable changes to the ran- mobile devices. -
PV204: Disk Encryption Lab
PV204: Disk encryption lab May 12, 2016, Milan Broz <[email protected]> Introduction Encryption can provide confidentiality and authenticity of user data. It can be implemented on several different layes, including application, file system or storage device. Application encryption examples are PGP or ZIP compression with password. Encryption of files (inside filesystem or through independent layer like Linux eCryptfs) provides more generic solution. Yet some parts (like filesystem metadata) are still unencrypted. However this solution provides encrypted data with private key per user. (Every user can have own directory encrypted by own key.) Encryption of the low-level storage (disk) is called Full Disk Encryption (FDE). It is completely transparent to the user (no need to choose what to encrypt – the whole disk is encrypted). The encrypted disk behaves as the same as a disk without encryption. The major disadvantage is that everyone who knows the password can read the whole disk. Often we combine FDE with another encryption layer. The primary use of FDE is to provide data confidentiality in power-down mode (stolen laptop does not leak user data). Once the disk is unlocked, the main encryption key remains in system, usually directly in system RAM. Exercise II will show how easy is to get this key from memory image of system. Another disadvantage of FDE is that it usually cannot guarantee integrity of data. Encryption is fully transparent and length-preserving, the ciphertext and plaintext device are of the same size. There is no space to store any integrity information. This allows attacks by direct modification of ciphertext. -
Linux on the Road
Linux on the Road Linux with Laptops, Notebooks, PDAs, Mobile Phones and Other Portable Devices Werner Heuser <wehe[AT]tuxmobil.org> Linux Mobile Edition Edition Version 3.22 TuxMobil Berlin Copyright © 2000-2011 Werner Heuser 2011-12-12 Revision History Revision 3.22 2011-12-12 Revised by: wh The address of the opensuse-mobile mailing list has been added, a section power management for graphics cards has been added, a short description of Intel's LinuxPowerTop project has been added, all references to Suspend2 have been changed to TuxOnIce, links to OpenSync and Funambol syncronization packages have been added, some notes about SSDs have been added, many URLs have been checked and some minor improvements have been made. Revision 3.21 2005-11-14 Revised by: wh Some more typos have been fixed. Revision 3.20 2005-11-14 Revised by: wh Some typos have been fixed. Revision 3.19 2005-11-14 Revised by: wh A link to keytouch has been added, minor changes have been made. Revision 3.18 2005-10-10 Revised by: wh Some URLs have been updated, spelling has been corrected, minor changes have been made. Revision 3.17.1 2005-09-28 Revised by: sh A technical and a language review have been performed by Sebastian Henschel. Numerous bugs have been fixed and many URLs have been updated. Revision 3.17 2005-08-28 Revised by: wh Some more tools added to external monitor/projector section, link to Zaurus Development with Damn Small Linux added to cross-compile section, some additions about acoustic management for hard disks added, references to X.org added to X11 sections, link to laptop-mode-tools added, some URLs updated, spelling cleaned, minor changes. -
Block Ciphers and the Data Encryption Standard
Lecture 3: Block Ciphers and the Data Encryption Standard Lecture Notes on “Computer and Network Security” by Avi Kak ([email protected]) January 26, 2021 3:43pm ©2021 Avinash Kak, Purdue University Goals: To introduce the notion of a block cipher in the modern context. To talk about the infeasibility of ideal block ciphers To introduce the notion of the Feistel Cipher Structure To go over DES, the Data Encryption Standard To illustrate important DES steps with Python and Perl code CONTENTS Section Title Page 3.1 Ideal Block Cipher 3 3.1.1 Size of the Encryption Key for the Ideal Block Cipher 6 3.2 The Feistel Structure for Block Ciphers 7 3.2.1 Mathematical Description of Each Round in the 10 Feistel Structure 3.2.2 Decryption in Ciphers Based on the Feistel Structure 12 3.3 DES: The Data Encryption Standard 16 3.3.1 One Round of Processing in DES 18 3.3.2 The S-Box for the Substitution Step in Each Round 22 3.3.3 The Substitution Tables 26 3.3.4 The P-Box Permutation in the Feistel Function 33 3.3.5 The DES Key Schedule: Generating the Round Keys 35 3.3.6 Initial Permutation of the Encryption Key 38 3.3.7 Contraction-Permutation that Generates the 48-Bit 42 Round Key from the 56-Bit Key 3.4 What Makes DES a Strong Cipher (to the 46 Extent It is a Strong Cipher) 3.5 Homework Problems 48 2 Computer and Network Security by Avi Kak Lecture 3 Back to TOC 3.1 IDEAL BLOCK CIPHER In a modern block cipher (but still using a classical encryption method), we replace a block of N bits from the plaintext with a block of N bits from the ciphertext. -
1 Perfect Secrecy of the One-Time Pad
1 Perfect secrecy of the one-time pad In this section, we make more a more precise analysis of the security of the one-time pad. First, we need to define conditional probability. Let’s consider an example. We know that if it rains Saturday, then there is a reasonable chance that it will rain on Sunday. To make this more precise, we want to compute the probability that it rains on Sunday, given that it rains on Saturday. So we restrict our attention to only those situations where it rains on Saturday and count how often this happens over several years. Then we count how often it rains on both Saturday and Sunday. The ratio gives an estimate of the desired probability. If we call A the event that it rains on Saturday and B the event that it rains on Sunday, then the intersection A ∩ B is when it rains on both days. The conditional probability of A given B is defined to be P (A ∩ B) P (B | A)= , P (A) where P (A) denotes the probability of the event A. This formula can be used to define the conditional probability of one event given another for any two events A and B that have probabilities (we implicitly assume throughout this discussion that any probability that occurs in a denominator has nonzero probability). Events A and B are independent if P (A ∩ B)= P (A) P (B). For example, if Alice flips a fair coin, let A be the event that the coin ends up Heads. If Bob rolls a fair six-sided die, let B be the event that he rolls a 3. -
Chapter 3. Booting Operating Systems
Chapter 3. Booting Operating Systems Abstract: Chapter 3 provides a complete coverage on operating systems booting. It explains the booting principle and the booting sequence of various kinds of bootable devices. These include booting from floppy disk, hard disk, CDROM and USB drives. Instead of writing a customized booter to boot up only MTX, it shows how to develop booter programs to boot up real operating systems, such as Linux, from a variety of bootable devices. In particular, it shows how to boot up generic Linux bzImage kernels with initial ramdisk support. It is shown that the hard disk and CDROM booters developed in this book are comparable to GRUB and isolinux in performance. In addition, it demonstrates the booter programs by sample systems. 3.1. Booting Booting, which is short for bootstrap, refers to the process of loading an operating system image into computer memory and starting up the operating system. As such, it is the first step to run an operating system. Despite its importance and widespread interests among computer users, the subject of booting is rarely discussed in operating system books. Information on booting are usually scattered and, in most cases, incomplete. A systematic treatment of the booting process has been lacking. The purpose of this chapter is to try to fill this void. In this chapter, we shall discuss the booting principle and show how to write booter programs to boot up real operating systems. As one might expect, the booting process is highly machine dependent. To be more specific, we shall only consider the booting process of Intel x86 based PCs. -
Self-Encrypting Deception: Weaknesses in the Encryption of Solid State Drives
Self-encrypting deception: weaknesses in the encryption of solid state drives Carlo Meijer Bernard van Gastel Institute for Computing and Information Sciences School of Computer Science Radboud University Nijmegen Open University of the Netherlands [email protected] and Institute for Computing and Information Sciences Radboud University Nijmegen Bernard.vanGastel@{ou.nl,ru.nl} Abstract—We have analyzed the hardware full-disk encryption full-disk encryption. Full-disk encryption software, especially of several solid state drives (SSDs) by reverse engineering their those integrated in modern operating systems, may decide to firmware. These drives were produced by three manufacturers rely solely on hardware encryption in case it detects support between 2014 and 2018, and are both internal models using the SATA and NVMe interfaces (in a M.2 or 2.5" traditional form by the storage device. In case the decision is made to rely on factor) and external models using the USB interface. hardware encryption, typically software encryption is disabled. In theory, the security guarantees offered by hardware encryp- As a primary example, BitLocker, the full-disk encryption tion are similar to or better than software implementations. In software built into Microsoft Windows, switches off software reality, we found that many models using hardware encryption encryption and completely relies on hardware encryption by have critical security weaknesses due to specification, design, and implementation issues. For many models, these security default if the drive advertises support. weaknesses allow for complete recovery of the data without Contribution. This paper evaluates both internal and external knowledge of any secret (such as the password). -
Zenworks 2017 Update 4 Troubleshooting Full Disk Encryption January 2019
ZENworks 2017 Update 4 Troubleshooting Full Disk Encryption January 2019 This document provides troubleshooting guidelines for common problems related to ZENworks Full Disk Encryption. If, after completing the troubleshooting steps, the problem is not resolved, you should contact Technical Support (https://www.novell.com/support/) for additional help. 1 Windows PE Emergency Recovery Disk (ERD) is not working Make sure you have installed the correct WAIK architecture (32-bit vs 64-bit) (Windows 7 only) If you manually created the ERD, use the PowerShell script provided in the Cool Solutions “Windows Powershell script to create a Windows PE emergency recovery disk for ZENworks Full Disk Encryption” article. Try creating the ERD using the ADK for Windows instead of Windows AIK. See “Creating a Windows PE Emergency Recovery Disk” in the ZENworks Full Disk Encryption Emergency Recovery Reference. Try burning the ERD to a DVD rather than a CD. 2 Issues with PBA login or boot sequence After pre-boot authentication occurs, the BIOS or UEFI settings must be correctly set for Windows. With unusual DMI hardware configurations, the standard ZENworks PBA boot method and Linux kernel configuration used to provide the BIOS settings, might not work, resulting in hardware that does not function correctly or is not recognized by Windows. Beginning in ZENworks 2017 Update 2, the Full Disk Encryption Agent includes DMI menu options to repair the boot sequence for issues relating to these DMI configurations. This menu is accessible by using the Ctrl + G keyboard command at a brief point when Full Disk Encryption is shown during a device restart. -
Linux Boot Loaders Compared
Linux Boot Loaders Compared L.C. Benschop May 29, 2003 Copyright c 2002, 2003, L.C. Benschop, Eindhoven, The Netherlands. Per- mission is granted to make verbatim copies of this document. This is version 1.1 which has some minor corrections. Contents 1 introduction 2 2 How Boot Loaders Work 3 2.1 What BIOS does for us . 3 2.2 Parts of a boot loader . 6 2.2.1 boot sector program . 6 2.2.2 second stage of boot loader . 7 2.2.3 Boot loader installer . 8 2.3 Loading the operating system . 8 2.3.1 Loading the Linux kernel . 8 2.3.2 Chain loading . 10 2.4 Configuring the boot loader . 10 3 Example Installations 11 3.1 Example root file system and kernel . 11 3.2 Linux Boot Sector . 11 3.3 LILO . 14 3.4 GNU GRUB . 15 3.5 SYSLINUX . 18 3.6 LOADLIN . 19 3.7 Where Can Boot Loaders Live . 21 1 4 RAM Disks 22 4.1 Living without a RAM disk . 22 4.2 RAM disk devices . 23 4.3 Loading a RAM disk at boot time . 24 4.4 The initial RAM disk . 24 5 Making Diskette Images without Diskettes 25 6 Hard Disk Installation 26 7 CD-ROM Installation 29 8 Conclusions 31 1 introduction If you use Linux on a production system, you will only see it a few times a year. If you are a hobbyist who compiles many kernels or who uses many operating systems, you may see it several times per day.