A Surfeit of SSH Cipher Suites
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FIPS 140-2 Non-Proprietary Security Policy
Kernel Crypto API Cryptographic Module version 1.0 FIPS 140-2 Non-Proprietary Security Policy Version 1.3 Last update: 2020-03-02 Prepared by: atsec information security corporation 9130 Jollyville Road, Suite 260 Austin, TX 78759 www.atsec.com © 2020 Canonical Ltd. / atsec information security This document can be reproduced and distributed only whole and intact, including this copyright notice. Kernel Crypto API Cryptographic Module FIPS 140-2 Non-Proprietary Security Policy Table of Contents 1. Cryptographic Module Specification ..................................................................................................... 5 1.1. Module Overview ..................................................................................................................................... 5 1.2. Modes of Operation ................................................................................................................................. 9 2. Cryptographic Module Ports and Interfaces ........................................................................................ 10 3. Roles, Services and Authentication ..................................................................................................... 11 3.1. Roles .......................................................................................................................................................11 3.2. Services ...................................................................................................................................................11 -
The Software Performance of Authenticated-Encryption Modes 1
An earlier version of this paper appears at Fast Software Encryption 2011 (FSE 2011). The Software Performance of Authenticated-Encryption Modes Ted Krovetz∗ Phillip Rogawayy March 21, 2011 Abstract We study the software performance of authenticated-encryption modes CCM, GCM, and OCB. Across a variety of platforms, we find OCB to be substantially faster than either alternative. For example, on an Intel i5 (\Clarkdale") processor, good implementations of CCM, GCM, and OCB encrypt at around 4.2 cpb, 3.7 cpb, and 1.5 cpb, while CTR mode requires about 1.3 cpb. Still we find room for algorithmic improvements to OCB, showing how to trim one blockcipher call (most of the time, assuming a counter-based nonce) and reduce latency. Our findings contrast with those of McGrew and Viega (2004), who claimed similar performance for GCM and OCB. Key words: authenticated encryption, cryptographic standards, encryption speed, modes of operation, CCM, GCM, OCB. 1 Introduction Background. Over the past few years, considerable effort has been spent constructing schemes for authenticated encryption (AE). One reason is recognition of the fact that a scheme that delivers both privacy and authenticity may be more efficient than the straightforward amalgamation of separate privacy and authenticity techniques. A second reason is the realization that an AE scheme is less likely to be incorrectly used than an encryption scheme designed for privacy alone. While other possibilities exist, it is natural to build AE schemes from blockciphers, employing some mode of operation. There are two approaches. In a composed (\two-pass") AE scheme one conjoins essentially separate privacy and authenticity modes. -
The Missing Difference Problem, and Its Applications to Counter Mode
The Missing Difference Problem, and its Applications to Counter Mode Encryption? Ga¨etanLeurent and Ferdinand Sibleyras Inria, France fgaetan.leurent,[email protected] Abstract. The counter mode (CTR) is a simple, efficient and widely used encryption mode using a block cipher. It comes with a security proof that guarantees no attacks up to the birthday bound (i.e. as long as the number of encrypted blocks σ satisfies σ 2n=2), and a matching attack that can distinguish plaintext/ciphertext pairs from random using about 2n=2 blocks of data. The main goal of this paper is to study attacks against the counter mode beyond this simple distinguisher. We focus on message recovery attacks, with realistic assumptions about the capabilities of an adversary, and evaluate the full time complexity of the attacks rather than just the query complexity. Our main result is an attack to recover a block of message with complexity O~(2n=2). This shows that the actual security of CTR is similar to that of CBC, where collision attacks are well known to reveal information about the message. To achieve this result, we study a simple algorithmic problem related to the security of the CTR mode: the missing difference problem. We give efficient algorithms for this problem in two practically relevant cases: where the missing difference is known to be in some linear subspace, and when the amount of data is higher than strictly required. As a further application, we show that the second algorithm can also be used to break some polynomial MACs such as GMAC and Poly1305, with a universal forgery attack with complexity O~(22n=3). -
Patent-Free Authenticated-Encryption As Fast As OCB
Patent-Free Authenticated-Encryption As Fast As OCB Ted Krovetz Computer Science Department California State University Sacramento, California, 95819 USA [email protected] Abstract—This paper presents an efficient authenticated encryp- VHASH hash family [4]. The resulting authenticated encryp- tion construction based on a universal hash function and block tion scheme peaks at 12.8 cpb, while OCB peaks at 13.9 cpb in cipher. Encryption is achieved via counter-mode while authenti- our experiments. The paper closes with a performance com- cation uses the Wegman-Carter paradigm. A single block-cipher parison of several well-known authenticated encryption algo- key is used for both operations. The construction is instantiated rithms [6]. using the hash functions of UMAC and VMAC, resulting in authenticated encryption with peak performance about ten per- cent slower than encryption alone. II. SECURITY DEFINITIONS We adopt the notions of security from [7], and summarize Keywords- Authenticated encryption, block-cipher mode-of- them less formally here. An authenticated encryption with as- operation, AEAD, UMAC, VMAC. sociated data (AEAD) scheme is a triple S = (K,E,D), where K is a set of keys, and E and D are encryption and decryption I. INTRODUCTION functions. Encryption occurs by computing E(k,n,h,p,f), which Traditionally when one wanted to both encrypt and authen- returns (c,t), for key k, nonce n, header h, plaintext m and ticate communications, one would encrypt the message under footer f. Ciphertext c is the encryption of p, and tag t authenti- one key and authenticate the resulting ciphertext under a sepa- cates h, c and f. -
Symmetric Key Cryptography PQCRYPTO Summer School on Post-Quantum Cryptography 2017
Symmetric Key Cryptography PQCRYPTO Summer School on Post-Quantum Cryptography 2017 Stefan Kölbl June 20th, 2017 DTU Compute, Technical University of Denmark Introduction to Symmetric Key Cryptography Symmetric Key Cryptography What can we do? • Encryption • Authentication (MAC) • Hashing • Random Number Generation • Digital Signature Schemes • Key Exchange 1 Authentication Authentication Message Authentication Code (MAC) Key Message MAC Tag • Produces a tag • Provide both authenticity and integrity • It should be hard to forge a valid tag. • Similar to hash but has a key • Similar to digital signature but same key 2 Authentication MAC Algorithm • Block Cipher Based (CBC-MAC) • Hash-based (HMAC, Sponge) • Universal Hashing (UMAC, Poly1305) 3 Authentication CBC-MAC M1 M2 Mi 0 EK EK EK T 4 Authentication Hash-based: • H(k jj m) • Okay with Sponge, fails with MD construction. • H(m jj k) • Collision on H allows to construct Tag collision. • HMAC: H(k ⊕ c1kj H(k ⊕ c2jjm)) 5 Authentication Universal Hashing (UMAC, Poly1305, …) • We need a universal hash function family H. • Parties share a secret member of H and key k. • Attacker does not know which one was chosen. Definition A set H of hash functions h : U ! N is universal iff 8x; y 2 U: 1 Pr (h(x) = h(y)) ≤ h2H jNj when h is chosen uniformly at random. 6 Authenticated Encryption In practice we always want Authenticated Encryption • Encryption does not protect against malicious alterations. • WEP [TWP07] • Plaintext recovery OpenSSH [APW09] • Recover TLS cookies [DR11] Problem Lot of things can go wrong when combining encryption and authentication. Note: This can allow to recover plaintext, forge messages.. -
On Comparing Side‑Channel Properties of AES and Chacha20 on Microcontrollers
This document is downloaded from DR‑NTU (https://dr.ntu.edu.sg) Nanyang Technological University, Singapore. On comparing side‑channel properties of AES and ChaCha20 on microcontrollers Najm, Zakaria; Jap, Dirmanto; Jungk, Bernhard; Picek, Stjepan; Bhasin, Shivam 2018 Najm, Z., Jap, D., Jungk, B., Picek, S., & Bhasin, S. (2018). On comparing side‑channel properties of AES and ChaCha20 on microcontrollers. 2018 IEEE Asia Pacific Conference on Circuits and Systems (APCCAS). doi:10.1109/APCCAS.2018.8605653 https://hdl.handle.net/10356/104628 https://doi.org/10.1109/APCCAS.2018.8605653 © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. The published version is available at: https://doi.org/10.1109/APCCAS.2018.8605653 Downloaded on 30 Sep 2021 18:00:37 SGT On Comparing Side-channel Properties of AES and ChaCha20 on Microcontrollers Zakaria Najm1,2, Dirmanto Jap1, Bernhard Jungk3, Stjepan Picek2, and Shivam Bhasin1 1Temasek Laboratories, Nanyang Technological University, Singapore 2Delft University of Technology, Delft, The Netherlands 3Independent Researcher fzakaria.najm,djap,[email protected], bernhard@projectstarfire.de, [email protected] Abstract—Side-channel attacks are a real threat to many secure When considering countermeasures, it is also the nonlinear systems. In this paper, we consider two ciphers used in the operation which is expensive to implement protected against automotive industry – AES and ChaCha20 and we evaluate their side-channel attacks, unlike other linear components of the resistance against side-channel attacks. -
ECE 435 – Network Engineering Lecture 4
ECE 435 { Network Engineering Lecture 4 Vince Weaver http://web.eece.maine.edu/~vweaver [email protected] 13 September 2018 Announcements • HW#1 was due. • HW#2 will be posted. Write a mini webserver. • Cybersecurity club Linux Security Lab on Saturday 1 WWW wrapup 2 What if Server Overloaded? • Slashdot effect (modern: HackerNews?) • caching/proxy { squid • Content Delivery Network { akami • Server farms 3 Security • SSL { Secure Socket Layer • Replaced by TLS (Transport Layer Security) • Port 443 for https • Public key encryption. 4 Setting Up a Web-server • Apache • Easy to do, more difficult to secure 5 Web Seach • Web-bots index the web. robots.txt file • Altavista, Hotbot, Excite, Inktomi, etc. • Curated search like Yahoo (people organize links rather than automatically search) • Google (1996 some machine in Stanford, 1997-1998) • MSN search 1999, rebranded Microsoft Bing 2009 6 Remote Connections 7 telnet/rlogin/rsh/ssh • telnet { login to remote system (tcp port 23) everything (including passwords) sent in plain text • rsh/rlogin { remote shell, remote login. (tcp port 514) Didn't even need password, could configure to let you run commands on remote machine. Security based if you had same username on both machines, assumption was getting root on a UNIX machine and connected to Ethernet was expensive/difficult 8 SSH secure shell • tcp port 22 • can login, run commands, tunnel tcp/ip, tunnel X11, file transfer (scp, sftp) • Large number of RFCs • Version 1: 1995, originally freeware but became private • Version 2: 2005, openBSD based on last free version • For security reasons there's a push to drop Version 1 • uses public-key cryptography • transport layer: arranges initial key exchange, server 9 authentication, key re-exchange • user authentication layer: can have password, or can set up keys to allow passwordless, DSA or RSA key pairs • connection layer: set up channels • lots of encryption types supported, old ones being obsoleted as found wanting • Various ssh servers/clients. -
Authenticated Encryption in SSH
Authenticated Encryption in SSH Kenny Paterson Information Security Group @kennyog; www.isg.rhul.ac.uk/~kp Overview (both lectures) • Secure channels and their properties • AEAD (revision) • AEAD ≠ secure channel – the [APW09] attack on SSH • The state of AEAD in SSH today • A new attack on CBC-mode in OpenSSH • Security analysis of other SSH and OpenSSH modes – CTR, ChaChaPoly, gEtM, AES-GCM. 2 Secure channels and their properties Why do we need secure channels? • Secure communications is the most common real- world application of cryptography today. • Secure communications systems are extremely widely-deployed in practice: • SSL/TLS, DTLS, IPsec, SSH, OpenVPN,… • WEP/WPA/WPA2 • GSM/UMTS/4g/LTE • Cryptocat, OTR, SilentCircle • OpenPGP, iMessage, Telegram, Signal, and a thousand other messaging apps • QUIC, MinimalT, TCPcrypt 4 Security properties • Confidentiality – privacy for data • Integrity – detection of data modification • Authenticity – assurance concerning the source of data 5 Some less obvious security properties • Anti-replay • Detection that messages have been repeated. • Detection of deletion • Detection that messages have been deleted by the adversary or dropped by the network. • Detection of re-0rdering • Ensuring that the relative order of messages in each direction on the secure channel is preserved. • Possibly re-ordering the event of violation. • Prevention of traffic-analysis. • Using traffic padding and length-hiding techniques. 6 Possible functionality requirements • Speedy • Low-memory • On-line/parallelisable crypto-operations • Performance is heavily hardware-dependent. • May have different algorithms for different platforms. • IPR-friendly • This issue has slowed down adoption of many otherwise good algorithms, e.g. OCB. • Easy to implement • Without introducing any side-channels. -
Stream Cipher Designs: a Review
SCIENCE CHINA Information Sciences March 2020, Vol. 63 131101:1–131101:25 . REVIEW . https://doi.org/10.1007/s11432-018-9929-x Stream cipher designs: a review Lin JIAO1*, Yonglin HAO1 & Dengguo FENG1,2* 1 State Key Laboratory of Cryptology, Beijing 100878, China; 2 State Key Laboratory of Computer Science, Institute of Software, Chinese Academy of Sciences, Beijing 100190, China Received 13 August 2018/Accepted 30 June 2019/Published online 10 February 2020 Abstract Stream cipher is an important branch of symmetric cryptosystems, which takes obvious advan- tages in speed and scale of hardware implementation. It is suitable for using in the cases of massive data transfer or resource constraints, and has always been a hot and central research topic in cryptography. With the rapid development of network and communication technology, cipher algorithms play more and more crucial role in information security. Simultaneously, the application environment of cipher algorithms is in- creasingly complex, which challenges the existing cipher algorithms and calls for novel suitable designs. To accommodate new strict requirements and provide systematic scientific basis for future designs, this paper reviews the development history of stream ciphers, classifies and summarizes the design principles of typical stream ciphers in groups, briefly discusses the advantages and weakness of various stream ciphers in terms of security and implementation. Finally, it tries to foresee the prospective design directions of stream ciphers. Keywords stream cipher, survey, lightweight, authenticated encryption, homomorphic encryption Citation Jiao L, Hao Y L, Feng D G. Stream cipher designs: a review. Sci China Inf Sci, 2020, 63(3): 131101, https://doi.org/10.1007/s11432-018-9929-x 1 Introduction The widely applied e-commerce, e-government, along with the fast developing cloud computing, big data, have triggered high demands in both efficiency and security of information processing. -
Reducing the Impact of Dos Attacks on Endpoint IP Security
Reducing the Impact of DoS Attacks on Endpoint IP Security Joseph D. Touch and Yi-Hua Edward Yang USC/ISI [email protected] / [email protected] 1 Abstract some attack traffic. These results also indicate that this technique becomes more effective as the algorithm IP security is designed to protect hosts from attack, becomes more computationally intensive, and suggest but can itself provide a way to overwhelm the that such hierarchical intra-packet defenses are needed resources of a host. One such denial of service (DoS) to avoid IPsec being itself an opportunity for attack. attack involves sending incorrectly signed packets to a host, which then consumes substantial CPU resources 2. Background to reject unwanted traffic. This paper quantifies the impact of such attacks and explores preliminary ways Performance has been a significant issue for to reduce that impact. Measurements of the impact of Internet security since its inception and affects the DoS attack traffic on PC hosts indicate that a single IPsec suite both at the IKE (session establishment) and attacker can reduce throughput by 50%. This impact IPsec (packets in a session) level [10][11]. This paper can be reduced to 20% by layering low-effort nonce focuses on the IPsec level, i.e., protection for validation on IPsec’s CPU-intensive cryptographic established sessions. Previous performance analysis of algorithms, but the choice of algorithm does not have HMAC-MD5 (Hashed-MAC, where MAC means as large an effect. This work suggests that effective keyed Message Authentication Code), HMAC-SHA1, DoS resistance requires a hierarchical defense using and 3DES showed that the cost of the cryptographic both nonces and strong cryptography at the endpoints, algorithms dwarfs other IPsec overheads [6] [7] [15]. -
Wind River® Vxworks® 7 Third Party License Notices
Wind River® VxWorks® 7 Third Party License Notices This document contains third party intellectual property (IP) notices for the BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY Wind River® VxWorks® 7 distribution. Certain licenses and license notices THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, may appear in other parts of the product distribution in accordance with the OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN license requirements. ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Trademarks All company, product and service names used in this software are for ACPICA identification purposes only. Version: 20170303 Component(s): Runtime Wind River and VxWorks are registered trademarks of Wind River Systems. Description: Provides code to implement ACPI specification in VxWorks. UNIX is a registered trademark of The Open Group. IBM and Bluemix are registered trademarks of the IBM Corporation. NOTICES: All other third-party trademarks are the property of their respective owners. 1. Copyright Notice Some or all of this work - Copyright (c) 1999 - 2016, Intel Corp. All rights reserved. Third Party Notices 2. License 2.1. This is your license from Intel Corp. under its intellectual property rights. You may have additional license terms from the party that provided you this software, covering your right to use that party's intellectual property rights. 64-Bit Dynamic Linker Version: 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a copy Component(s): Runtime of the source code appearing in this file ("Covered Code") an irrevocable, Description: The dynamic linker is used to load shared libraries. -
Implementation of Hash Function for Cryptography (Rsa Security)
International Journal For Technological Research In Engineering Volume 4, Issue 6, February-2017 ISSN (Online): 2347 - 4718 IMPLEMENTATION OF HASH FUNCTION FOR CRYPTOGRAPHY (RSA SECURITY) Syed Fateh Reza1, Mr. Prasun Das2 1M.Tech. (ECE), 2Assistant Professor (ECE), Bitm,Bolpur ABSTRACT: In this thesis, a new method for expected to have a unique hash code and it should be implementing cryptographic hash functions is proposed. generally difficult for an attacker to find two messages with This method seeks to improve the speed of the hash the same hash code. function particularly when a large set of messages with Mathematically, a hash function (H) is defined as follows: similar blocks such as documents with common Headers H: {0, 1}* → {0, 1}n are to be hashed. The method utilizes the peculiar run-time In this notation, {0, 1}* refers to the set of binary elements configurability Feature of FPGA. Essentially, when a block of any length including the empty string while {0, 1}n refers of message that is commonly hashed is identified, the hash to the set of binary elements of length n. Thus, the hash value is stored in memory so that in subsequent occurrences function maps a set of binary elements of arbitrary length to of The message block, the hash value does not need to be a set of binary elements of fixed length. Similarly, the recomputed; rather it is Simply retrieved from memory, thus properties of a hash function are defined as follows: giving a significant increase in speed. The System is self- x {0, 1}*; y {0,1}n learning and able to dynamically build on its knowledge of Pre-image resistance: given y= H(x), it should be difficult to frequently Occurring message blocks without intervention find x.