Encrypted key exchange: password-based protocols secure against dictionary attacks
04 May 1992-pp 72-84
TL;DR: A combination of asymmetric (public-key) and symmetric (secret- key) cryptography that allow two parties sharing a common password to exchange confidential and authenticated information over an insecure network is introduced.
Abstract: Classic cryptographic protocols based on user-chosen keys allow an attacker to mount password-guessing attacks. A combination of asymmetric (public-key) and symmetric (secret-key) cryptography that allow two parties sharing a common password to exchange confidential and authenticated information over an insecure network is introduced. In particular, a protocol relying on the counter-intuitive motion of using a secret key to encrypt a public key is presented. Such protocols are secure against active attacks, and have the property that the password is protected against offline dictionary attacks. >
Citations
More filters
Posted Content•
TL;DR: In 2009, Abdalla et al. as discussed by the authors proposed a password-authenticated key exchange (PAKE) secure against adaptive adversaries in the universal composability (UC) framework.
Abstract: In 2009, Abdalla et al. proposed a reasonably practical password-authenticated key exchange (PAKE) secure against adaptive adversaries in the universal composability (UC) framework. It exploited the Canetti-Fischlin methodology for commitments and the Cramer-Shoup smooth projective hash functions (SPHFs), following the Gennaro-Lindell approach for PAKE. In this paper, we revisit the notion of non-interactive commitments, with a new formalism that implies UC security. In addition, we provide a quite efficient instantiation. We then extend our formalism to SPHF-friendly commitments. We thereafter show that it allows a blackbox application to oneround PAKE and oblivious transfer (OT), still secure in the UC framework against adaptive adversaries, assuming reliable erasures and a single global common reference string, even for multiple sessions. Our instantiations are more efficient than the Abdalla et al. PAKE in Crypto 2009 and the recent OT protocol proposed by Choi et al. in PKC 2013. Furthermore, the new PAKE instantiation is the first one-round scheme achieving UC security against adaptive adversaries.
6 citations
Posted Content•
6 citations
01 Jan 2006
TL;DR: This paper proposes a new protocol for dynamic multiparty password key agreement, based on Elliptic Curve Cryptography, which can enhance and optimize the disaster relief efforts after a natural disaster or a terrorist attack.
Abstract: Ad-hoc networking is a relatively new operating mode for rapid mobile host interconnection. However, it suffers from the lack of a fixed infrastructure that forces each adhoc host to rely on each other, in order to maintain the network stability and functionality. This singularity of adhoc networks introduces several issues, most of which concern the system’s security. This paper focuses on investigating the security threats of ad-hoc networks together with their unique ability to meet specific emergency requirements, such as the rapid deployment of emergency networks which can enhance and optimize the disaster relief efforts after a natural disaster or a terrorist attack. Moreover this particular type of networks can be found very efficient in military environments where the cellular/PCS services may not be available. Considering the difficulty of establishing a secure network where the impacted group members share no prior electronic information, and moreover considering how this can be achieved through the most reliable, secure and efficient way, we propose a new protocol for dynamic multiparty password key agreement, based on Elliptic Curve Cryptography.
6 citations
Cites background from "Encrypted key exchange: password-ba..."
...In [2] Bellovin and Merritt proposed a password authenticated key exchange which operates in the following way....
[...]
...Bellowin and Merrit [2] proposed a protocol called Encrypted Key Exchange(EKE) where a strong shared key is derived from a weak one....
[...]
01 Jan 2013
TL;DR: This paper identified an inherent flaw in the design of Nam et al.
Abstract: Protocols for password-based authenticated key exchange (PAKE) enable two or more parties communicating over a public network to build a secure communication channel using their easy-to-remember passwords. However, off-line dictionary attacks have always been a major security concern in designing such password-based protocols. Compared with the twoparty setting, the concern is significantly increased in the three-party setting where insider attacks may be mounted. In this paper, we identified an inherent flaw in the design of Nam et al.’s three-party PAKE protocol (IEEE Communications Letters, 13(3), 2009) and Lu and Cao’s protocol (Computers & Security, 26(1), 2007) and demonstrated that both protocols are susceptible to a previously unpublished off-line dictionary attack. We hope that by identifying this design flaw, similar structural mistakes can be avoided in future design. We conclude the paper with a simple countermeasure.
6 citations
Cites background from "Encrypted key exchange: password-ba..."
...Protocols for password-based authenticated key exchange (PAKE) enable two or more parties communicating over a public network to generate a high-entropy cryptographic key (also known as a session key) from their low-entropy passwords which are easy for humans to remember [6, 5, 11, 9, 13, 8, 7, 2, 4, 3, 1, 12, 16, 10, 15, 17]....
[...]
TL;DR: It is proved that the RSA-AKE2 protocol is secure against replacement attacks based on the number theory results and it is shown that it is provably secure in the random oracle model by showing the reduction to the RSA one-wayness.
Abstract: Secure channels can be realized by an authenticated key exchange (AKE) protocol that generates authenticated session keys between the involving parties. In [32], Shin et al., proposed a new kind of AKE (RSA-AKE) protocol whose goal is to provide high efficiency and security against leakage of stored secrets as much as possible. Let us consider more powerful attacks where an adversary completely controls the communications and the stored secrets (the latter is denoted by “replacement” attacks). In this paper, we first show that the RSA-AKE protocol [32] is no longer secure against such an adversary. The main contributions of this paper are as follows: (1) we propose an RSA-based leakage-resilient AKE (RSA-AKE2) protocol that is secure against active attacks as well as replacement attacks; (2) we prove that the RSA-AKE2 protocol is secure against replacement attacks based on the number theory results; (3) we show that it is provably secure in the random oracle model, by showing the reduction to the RSA one-wayness, under an extended model that covers active attacks and replacement attacks; (4) in terms of efficiency, the RSA-AKE2 protocol is comparable to [32] in the sense that the client needs to compute only one modular multiplication with pre-computation; and (5) we also discuss about extensions of the RSA-AKE2 protocol for several security properties (i.e., synchronization of stored secrets, privacy of client and solution to server compromise-impersonation attacks).
6 citations
References
More filters
TL;DR: This paper suggests ways to solve currently open problems in cryptography, and discusses how the theories of communication and computation are beginning to provide the tools to solve cryptographic problems of long standing.
Abstract: Two kinds of contemporary developments in cryptography are examined. Widening applications of teleprocessing have given rise to a need for new types of cryptographic systems, which minimize the need for secure key distribution channels and supply the equivalent of a written signature. This paper suggests ways to solve these currently open problems. It also discusses how the theories of communication and computation are beginning to provide the tools to solve cryptographic problems of long standing.
14,980 citations
"Encrypted key exchange: password-ba..." refers background or methods in this paper
...ElGamal’s algorithm is derived from the DiffieHellman exponential key exchange protocol[2]; accordingly, we will review the latter first....
[...]
...And even this risk is minimal if B performs certain checks to guard against easily-solvable choices: that β is indeed prime, that it is large enough (and hence not susceptible to precalculation of tables), that β − 1 have at least one large prime factor (to guard against Pohlig and Hellman’s algorithm[13]), and that α is a primitive root of GF (β)....
[...]
...The use given above for asymmetric encryption — simply using it to pass a key for a symmetric encryption system — is an example of what Diffie and Hellman[2] call a public key distribution system....
[...]
...It works especially well with exponential key exchange [2]....
[...]
TL;DR: An encryption method is presented with the novel property that publicly revealing an encryption key does not thereby reveal the corresponding decryption key.
Abstract: An encryption method is presented with the novel property that publicly revealing an encryption key does not thereby reveal the corresponding decryption key. This has two important consequences: (1) Couriers or other secure means are not needed to transmit keys, since a message can be enciphered using an encryption key publicly revealed by the intented recipient. Only he can decipher the message, since only he knows the corresponding decryption key. (2) A message can be “signed” using a privately held decryption key. Anyone can verify this signature using the corresponding publicly revealed encryption key. Signatures cannot be forged, and a signer cannot later deny the validity of his signature. This has obvious applications in “electronic mail” and “electronic funds transfer” systems. A message is encrypted by representing it as a number M, raising M to a publicly specified power e, and then taking the remainder when the result is divided by the publicly specified product, n, of two large secret primer numbers p and q. Decryption is similar; only a different, secret, power d is used, where e * d ≡ 1(mod (p - 1) * (q - 1)). The security of the system rests in part on the difficulty of factoring the published divisor, n.
14,659 citations
"Encrypted key exchange: password-ba..." refers methods in this paper
...Section 2 describes the asymmetric cryptosystem variant and implementations using RSA[ 3 ] and ElGamal[4]....
[...]
...We will use RSA[ 3 ] to illustrate the difficulties....
[...]
23 Aug 1985
TL;DR: A new signature scheme is proposed, together with an implementation of the Diffie-Hellman key distribution scheme that achieves a public key cryptosystem that relies on the difficulty of computing discrete logarithms over finite fields.
Abstract: A new signature scheme is proposed, together with an implementation of the Diffie-Hellman key distribution scheme that achieves a public key cryptosystem. The security of both systems relies on the difficulty of computing discrete logarithms over finite fields.
7,514 citations
19 Aug 1984
TL;DR: In this article, a new signature scheme is proposed together with an implementation of the Diffie-Hellman key distribution scheme that achieves a public key cryptosystem and the security of both systems relies on the difficulty of computing discrete logarithms over finite fields.
Abstract: A new signature scheme is proposed together with an implementation of the Diffie - Hellman key distribution scheme that achieves a public key cryptosystem. The security of both systems relies on the difficulty of computing discrete logarithms over finite fields.
2,351 citations
Book•
01 Jan 1982TL;DR: The goal of this book is to introduce the mathematical principles of data security and to show how these principles apply to operating systems, database systems, and computer networks.
Abstract: From the Preface (See Front Matter for full Preface)
Electronic computers have evolved from exiguous experimental enterprises in the 1940s to prolific practical data processing systems in the 1980s. As we have come to rely on these systems to process and store data, we have also come to wonder about their ability to protect valuable data.
Data security is the science and study of methods of protecting data in computer and communication systems from unauthorized disclosure and modification. The goal of this book is to introduce the mathematical principles of data security and to show how these principles apply to operating systems, database systems, and computer networks. The book is for students and professionals seeking an introduction to these principles. There are many references for those who would like to study specific topics further.
Data security has evolved rapidly since 1975. We have seen exciting developments in cryptography: public-key encryption, digital signatures, the Data Encryption Standard (DES), key safeguarding schemes, and key distribution protocols. We have developed techniques for verifying that programs do not leak confidential data, or transmit classified data to users with lower security clearances. We have found new controls for protecting data in statistical databases--and new methods of attacking these databases. We have come to a better understanding of the theoretical and practical limitations to security.
1,937 citations
"Encrypted key exchange: password-ba..." refers background in this paper
...Can such a random odd number less than a known n be distinguished from a valid public key e? Assume that p and q are chosen to be of the form 2p′ + 1 and 2q′ + 1, where p′ and q′ are primes, a choice that is recommended for other reasons [9]....
[...]