Computational Security and the Economics of Password Hacking
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GPU-Based Password Cracking on the Security of Password Hashing Schemes Regarding Advances in Graphics Processing Units
Radboud University Nijmegen Faculty of Science Kerckhoffs Institute Master of Science Thesis GPU-based Password Cracking On the Security of Password Hashing Schemes regarding Advances in Graphics Processing Units by Martijn Sprengers [email protected] Supervisors: Dr. L. Batina (Radboud University Nijmegen) Ir. S. Hegt (KPMG IT Advisory) Ir. P. Ceelen (KPMG IT Advisory) Thesis number: 646 Final Version Abstract Since users rely on passwords to authenticate themselves to computer systems, ad- versaries attempt to recover those passwords. To prevent such a recovery, various password hashing schemes can be used to store passwords securely. However, recent advances in the graphics processing unit (GPU) hardware challenge the way we have to look at secure password storage. GPU's have proven to be suitable for crypto- graphic operations and provide a significant speedup in performance compared to traditional central processing units (CPU's). This research focuses on the security requirements and properties of prevalent pass- word hashing schemes. Moreover, we present a proof of concept that launches an exhaustive search attack on the MD5-crypt password hashing scheme using modern GPU's. We show that it is possible to achieve a performance of 880 000 hashes per second, using different optimization techniques. Therefore our implementation, executed on a typical GPU, is more than 30 times faster than equally priced CPU hardware. With this performance increase, `complex' passwords with a length of 8 characters are now becoming feasible to crack. In addition, we show that between 50% and 80% of the passwords in a leaked database could be recovered within 2 months of computation time on one Nvidia GeForce 295 GTX. -
Security + Encryption Standards
Security + Encryption Standards Author: Joseph Lee Email: joseph@ ripplesoftware.ca Mobile: 778-725-3206 General Concepts Forward secrecy / perfect forward secrecy • Using a key exchange to provide a new key for each session provides improved forward secrecy because if keys are found out by an attacker, past data cannot be compromised with the keys Confusion • Cipher-text is significantly different than the original plaintext data • The property of confusion hides the relationship between the cipher-text and the key Diffusion • Is the principle that small changes in message plaintext results in large changes in the cipher-text • The idea of diffusion is to hide the relationship between the cipher-text and the plaintext Secret-algorithm • A proprietary algorithm that is not publicly disclosed • This is discouraged because it cannot be reviewed Weak / depreciated algorithms • An algorithm that can be easily "cracked" or defeated by an attacker High-resiliency • Refers to the strength of the encryption key if an attacker discovers part of the key Data-in-transit • Data sent over a network Data-at-rest • Data stored on a medium Data-in-use • Data being used by an application / computer system Out-of-band KEX • Using a medium / channel for key-exchange other than the medium the data transfer is taking place (phone, email, snail mail) In-band KEX • Using the same medium / channel for key-exchange that the data transfer is taking place Integrity • Ability to determine the message has not been altered • Hashing algorithms manage Authenticity -
Implementation and Performance Analysis of PBKDF2, Bcrypt, Scrypt Algorithms
Implementation and Performance Analysis of PBKDF2, Bcrypt, Scrypt Algorithms Levent Ertaul, Manpreet Kaur, Venkata Arun Kumar R Gudise CSU East Bay, Hayward, CA, USA. [email protected], [email protected], [email protected] Abstract- With the increase in mobile wireless or data lookup. Whereas, Cryptographic hash functions are technologies, security breaches are also increasing. It has used for building blocks for HMACs which provides become critical to safeguard our sensitive information message authentication. They ensure integrity of the data from the wrongdoers. So, having strong password is that is transmitted. Collision free hash function is the one pivotal. As almost every website needs you to login and which can never have same hashes of different output. If a create a password, it’s tempting to use same password and b are inputs such that H (a) =H (b), and a ≠ b. for numerous websites like banks, shopping and social User chosen passwords shall not be used directly as networking websites. This way we are making our cryptographic keys as they have low entropy and information easily accessible to hackers. Hence, we need randomness properties [2].Password is the secret value from a strong application for password security and which the cryptographic key can be generated. Figure 1 management. In this paper, we are going to compare the shows the statics of increasing cybercrime every year. Hence performance of 3 key derivation algorithms, namely, there is a need for strong key generation algorithms which PBKDF2 (Password Based Key Derivation Function), can generate the keys which are nearly impossible for the Bcrypt and Scrypt. -
A New Approach in Expanding the Hash Size of MD5
374 International Journal of Communication Networks and Information Security (IJCNIS) Vol. 10, No. 2, August 2018 A New Approach in Expanding the Hash Size of MD5 Esmael V. Maliberan, Ariel M. Sison, Ruji P. Medina Graduate Programs, Technological Institute of the Philippines, Quezon City, Philippines Abstract: The enhanced MD5 algorithm has been developed by variants and RIPEMD-160. These hash algorithms are used expanding its hash value up to 1280 bits from the original size of widely in cryptographic protocols and internet 128 bit using XOR and AND operators. Findings revealed that the communication in general. Among several hashing hash value of the modified algorithm was not cracked or hacked algorithms mentioned above, MD5 still surpasses the other during the experiment and testing using powerful bruteforce, since it is still widely used in the domain authentication dictionary, cracking tools and rainbow table such as security owing to its feature of irreversible [41]. This only CrackingStation, Hash Cracker, Cain and Abel and Rainbow Crack which are available online thus improved its security level means that the confirmation does not need to demand the compared to the original MD5. Furthermore, the proposed method original data but only need to have an effective digest to could output a hash value with 1280 bits with only 10.9 ms confirm the identity of the client. The MD5 message digest additional execution time from MD5. algorithm was developed by Ronald Rivest sometime in 1991 to change a previous hash function MD4, and it is commonly Keywords: MD5 algorithm, hashing, client-server used in securing data in various applications [27,23,22]. -
How to Break EAP-MD5
How to Break EAP-MD5 Fanbao Liu and Tao Xie School of Computer, National University of Defense Technology, Changsha, 410073, Hunan, P.R. China [email protected] Abstract. We propose an efficient attack to recover the passwords, used to authenticate the peer by EAP-MD5, in the IEEE 802.1X network. First, we recover the length of the used password through a method called length recovery attack by on-line queries. Second, we crack the known length password using a rainbow table pre-computed with a fixed challenge, which can be done efficiently with great probability through off-line computations. This kind of attack can also be implemented suc- cessfully even if the underlying hash function MD5 is replaced with SHA- 1 or even SHA-512. Keywords: EAP-MD5, IEEE 802.1X, Challenge and Response, Length Recovery, Password Cracking, Rainbow Table. 1 Introduction IEEE 802.1X [6] is an IEEE Standard for port-based Network Access Con- trol, which provides an authentication mechanism to devices wishing to attach to a Local Area Network (LAN) or Wireless Local Area Network (WLAN). IEEE 802.1X defines the encapsulation of the Extensible Authentication Proto- col (EAP) [4] over IEEE 802 known as “EAP over LAN” (EAPoL). IEEE 802.1X authentication involves three parties: a peer, an authenticator and an authentica- tion server. The peer is a client device that wishes to attach to the LAN/WLAN. The authenticator is a network device, such as a Wireless Access Point (WAP), and the authentication server is typically a host running software supporting the Remote Authentication Dial In User Service (RADIUS) and EAP proto- cols. -
Rainbow Tables
Rainbow Tables Yukai Zang Division of Science and Mathematics University of Minnesota, Morris Morris, Minnesota, USA 56267 [email protected] Table of contents – Introduction & Background – Rainbow table – Create rainbow tables (offline stage) – Use rainbow tables (online stage) – Tests – Conclusion Table of contents – Introduction & Background – Rainbow table – Create rainbow tables (offline stage) – Use rainbow tables (online stage) – Tests – Conclusion Introduction & Background Introduction & Background Your password Hashed value (plain-text) 4C5E 9S8D D8S9 Fox Hash function 5T8V A7SE ASD9 Data base Introduction & Background – Hash function Arbitrary Length Input – Map data of arbitrary size onto data of fixed size Hash Function Fixed Length Output Introduction & Background – Cryptographic hash function – Same plain-text result in same hashed value; Cryptographic 4C5E 9S8D D8S9 Fox Hash function 5T8V A7SE ASD9 Introduction & Background – Cryptographic hash function – Same plain-text result in same hashed value; – Fast to compute; – Infeasible to revert back to plain-text from hashed value; Cryptographic 4C5E 9S8D D8S9 Fox Hash function 5T8V A7SE ASD9 Introduction & Background – Cryptographic hash function – Same plain-text result in same hashed value; – Fast to compute; – Infeasible to revert back to plain-text from hashed value; – Small change(s) in plain-text will cause huge changes in hashed value; Introduction & Background – Cryptographic hash function – Small change(s) in plain-text will cause huge changes in hashed value; Introduction & Background Introduction & Background – Cryptographic hash function – Same plain-text result in same hashed value; – Fast to compute; – Infeasible to revert back to plain-text from hashed value; – Small change(s) in plain-text will cause huge changes in hashed value; – Infeasible to find two different plain-text with the same hashed value. -
How to Handle Rainbow Tables with External Memory
How to Handle Rainbow Tables with External Memory Gildas Avoine1;2;5, Xavier Carpent3, Barbara Kordy1;5, and Florent Tardif4;5 1 INSA Rennes, France 2 Institut Universitaire de France, France 3 University of California, Irvine, USA 4 University of Rennes 1, France 5 IRISA, UMR 6074, France [email protected] Abstract. A cryptanalytic time-memory trade-off is a technique that aims to reduce the time needed to perform an exhaustive search. Such a technique requires large-scale precomputation that is performed once for all and whose result is stored in a fast-access internal memory. When the considered cryptographic problem is overwhelmingly-sized, using an ex- ternal memory is eventually needed, though. In this paper, we consider the rainbow tables { the most widely spread version of time-memory trade-offs. The objective of our work is to analyze the relevance of storing the precomputed data on an external memory (SSD and HDD) possibly mingled with an internal one (RAM). We provide an analytical evalua- tion of the performance, followed by an experimental validation, and we state that using SSD or HDD is fully suited to practical cases, which are identified. Keywords: time memory trade-off, rainbow tables, external memory 1 Introduction A cryptanalytic time-memory trade-off (TMTO) is a technique introduced by Martin Hellman in 1980 [14] to reduce the time needed to perform an exhaustive search. The key-point of the technique resides in the precomputation of tables that are then used to speed up the attack itself. Given that the precomputation phase is much more expensive than an exhaustive search, a TMTO makes sense in a few scenarios, e.g., when the adversary has plenty of time for preparing the attack while she has a very little time to perform it, the adversary must repeat the attack many times, or the adversary is not powerful enough to carry out an exhaustive search but she can download precomputed tables. -
Authentication, Authorization and Transport Layer Security
Universidade de Brasília Instituto de Ciências Exatas Departamento de Ciência da Computação Security of a NoSQL database: authentication, authorization and transport layer security Bruno Jorge S. Rodrigues Monograph presented as a partial requirement for the conclusion of the Course of Computer Engineering Supervisor Prof. Dr. Rodrigo Bonifácio de Almeida Brasília 2019 Universidade de Brasília Instituto de Ciências Exatas Departamento de Ciência da Computação Security of a NoSQL database: authentication, authorization and transport layer security Bruno Jorge S. Rodrigues Monograph presented as a partial requirement for the conclusion of the Course of Computer Engineering Prof. Dr. Rodrigo Bonifácio de Almeida (Supervisor) CIC/UnB Prof. Dr. Donald Knuth Dr. Leslie Lamport Stanford University Microsoft Research Prof. Dr. José Edil Coordinator of the Course of Computer Engineering Brasília, January 25, 2019 Dedication This work is dedicated to all the people who supported me until here. This is dedicated to God in the first place, for blessing me throughout this path that I have been crossing until here (1 Corinthians 10:31). This is dedicated to all my family, especially my father, Dimas, and my mother, Odilma, for loving me in first place, and for giving me strength, courage and the resources that I needed to get here without thinking twice. This is dedicated to Gabriella, for making me smile in my darkest moments, even when she was not in the best days as well. This is dedicated to all my friends, who made my days happier and also made this path easier to cross. I love you all, and you are very important to me! iii Acknowledgements First of all, I thank God for His mercies and blessings, for His care and for each door that was opened and also for every door that was closed. -
Breaking GSM with Rainbow Tables
Steven Meyer March 2010 Breaking GSM with rainbow Tables Abstract Since 1998 the GSM security has been academically broken but no real attack has ever been done until in 2008 when two engineers of Pico Computing (FPGA manufacture) revealed that they could break the GSM encryption in 30 seconds with 200’000$ hardware and precomputed rainbow tables. Since then the hardware was either available for rich people only or was confiscated by government agencies. So Chris Paget and Karsten Nohl decided to react and do the same thing but in a distributed open source form (on torrent). This way everybody could “enjoy” breaking GSM security and operators will be forced to upgrade the GSM protocol that is being used by more than 4 billion users and that is more than 20 years old. GSM Security When an operator signs a contract with a client, he gives the client a SIM card that contains firstly the IMSI (International Mobile Subscriber Identity) which is a unique 15 digit number that indicates the country, operator and mobile number and secondly a secret 128 bit key that is used for authentication and encryption. With these two elements, the operator pretends to guarantee Authentication (unidirectional) and privacy (that will be proven broken) of cell phone users. When a cell phone is connecting to a network there is a phase of authentication (the bill has to be sent to the right person). The phone first sends his IMSI to the network; the network then forwards it to the home operator, if they are different (for example while traveling abroad). -
Hybrid Password Authentication System
IOSR Journal of Computer Engineering (IOSR-JCE) e-ISSN: 2278-0661,p-ISSN: 2278-8727, Volume 22, Issue 4, Ser. I (Jul. – Aug. 2020), PP 42-51 www.iosrjournals.org Hybrid Password Authentication System 1 2 3 Harish Manikandan Balaji , Abisek K.S , Dharmesh Gopinath 1,2,3(Computer Science and Engineering, Anna University, India) Abstract: The storage and handling of passwords is a vital part of security systems. We introduce a novel approach for password authentication to store and handle passwords securely, which could be seamlessly, merged with existing security systems. This approach protects the genuine plaintext password from being discovered by a malicious actor even if the database storing the passwords suffers a data breach. The data breach could be a result of an unpatched or zero-day vulnerability. A plaintext password is hashed using a hash function. The hash is then split into two parts. One part is used to create a series of patterns (or) Anti-passwords involving the use of an Anti-password algorithm, which are then stored securely in a database. The other part is encrypted using AES algorithm. The encryption and the patterns together create two layers of security making it harder to crack through and access the passwords. The analysis and complexity of the system shows that the encrypted passwords can resist lookup attacks and provide even stronger protection against dictionary attacks. It should also be mentioned that the system combines the cryptographic hash function, patterns, and encryption, without requiring anything more than just the password. Key Word: Advanced Encryption Standard (AES); Anti-password; Negative Database (NDB); Hybrid password authentication system (HPAS). -
Modified SHA1: a Hashing Solution to Secure Web Applications Through Login Authentication
36 International Journal of Communication Networks and Information Security (IJCNIS) Vol. 11, No. 1, April 2019 Modified SHA1: A Hashing Solution to Secure Web Applications through Login Authentication Esmael V. Maliberan Graduate Studies, Surigao del Sur State University, Philippines Abstract: The modified SHA1 algorithm has been developed by attack against the SHA-1 hash function, generating two expanding its hash value up to 1280 bits from the original size of different PDF files. The research study conducted by [9] 160 bit. This was done by allocating 32 buffer registers for presented a specific freestart identical pair for SHA-1, i.e. a variables A, B, C and D at 5 bytes each. The expansion was done by collision within its compression function. This was the first generating 4 buffer registers in every round inside the compression appropriate break of the SHA-1, extending all 80 out of 80 function for 8 times. Findings revealed that the hash value of the steps. This attack was performed for only 10 days of modified algorithm was not cracked or hacked during the experiment and testing using powerful online cracking tool, brute computation on a 64-GPU. Thus, SHA1 algorithm is not force and rainbow table such as Cracking Station and Rainbow anymore safe in login authentication and data transfer. For Crack and bruteforcer which are available online thus improved its this reason, there were enhancements and modifications security level compared to the original SHA1. being developed in the algorithm in order to solve these issues [10, 11]. [12] proposed a new approach to enhance Keywords: SHA1, hashing, client-server communication, MD5 algorithm combined with SHA compression function modified SHA1, hacking, brute force, rainbow table that produced a 256-bit hash code. -
Cryptography Lecture 8 Digital Signatures, Hash Functions a Message Authentication Code Is What You Get from Symmetric Cryptography
Cryptography Lecture 8 Digital signatures, hash functions A Message Authentication Code is what you get from symmetric cryptography A MAC is used to prevent Eve from creating a new message and inserting it instead of Alice’s message Key Key Alice Create MAC Verify MAC Bob Eve Signature vs MAC A MAC, Message Authentication Code, preserves data integrity, • i.e., it ensures that creation and any changes of the message have been made by authorised entities Only the authorised entities can check a MAC, and all who can • check can also change the data In most legally interesting cases, you want to be able to verify that • one single individual wrote something Also, in many situations it is good if everyone is able to check the • signature Digital signatures In asymmetric ciphers, one single individual holds the private key, • while everyone can get the public key So if you encrypt with the private key, and send both cryptogram • and message, anyone can check that “decryption” with the public key does indeed create the message Note that some public key systems do not allow “encryption” with • the private key Most systems can be modified to generate and verify signatures • A digital signature can be created using asymmetric cryptography Used to prevent Eve from creating messages and present them as written by of Alice Private Public signing verification key key Create Verify Alice Anyone signature signature Eve Digital signatures A digital signature should not only be tied to the signing user, but • also to the message The example of encrypting