Committing Encryption and Publicly-Verifiable SignCryption
نویسندگان
چکیده
Encryption is often conceived as a committing process, in the sense that the ciphertext may serve as a commitment to the plaintext. But this does not follow from the standard definitions of secure encryption. We define and construct symmetric and asymmetric committing encryption schemes, enabling publicly verifiable non-repudiation. Committing encryption eliminates key-spoofing attacks and has also the robustness to be signed afterwards. Our constructions are very efficient and practical. In particular, we show that most popular asymmetric encryption schemes, e.g. RSA, are committing encryption schemes; we also have an (efficient) construction given an arbitrary asymmetric encryption scheme. Our construction of symmetric committing encryption retains the efficiency of the symmetric encryption for realtime operations, although it uses few public key signatures in the setup phase. Finally, we investigate how to achieve both confidentiality and non-repudiation, and present a publicly verifiable signcryption scheme. Contrary to previous signcryption schemes, which are not publicly verifiable, our publicly verifiable signcryption supports nonrepudiation. We construct a simple and efficient publicly verifiable signcryption scheme based on a new composition method which we call “commit-encrypt-then-sign” (CEtS) that preserves security properties of both committing encryption and digital signature schemes.
منابع مشابه
Generic Constructions for Verifiable Signcryption
Signcryption is a primitive which simultaneously performs the functions of both signature and encryption in a way that is more efficient than signing and encrypting separately. We study in this paper constructions of signcryption schemes from basic cryptographic mechanisms; our study concludes that the known constructions require expensive encryption in order to attain confidentiality, however ...
متن کاملEfficient Identity Based Public Verifiable Signcryption Scheme
Signcryption is a cryptographic primitive which performs encryption and signature in a single logical step. In conventional signcryption only receiver of the signcrypted text can verify the authenticity of the origin i.e. signature of the sender on the message after decrypting the cipher text. In public verifiable signcryption scheme anyone can verify the authenticity of the origin who can acce...
متن کاملIdentity based signcryption scheme without random oracles
Signcryption is a cryptographic primitive which performs encryption and signature in a single logical step with the cost lower than signature-then-encryption approach.. In this paper we gave attacks on confidentiality and unforgeability of two identity based signcryption schemes without random oracles. Further we proposed an improved identity based signcryption scheme without random oracles. We...
متن کاملAn Efficient and Publicly Verifiable Id-Based Multi-Signcryption Scheme
Multi-signcryption is used when different senders wants to authenticate a single message without revealing it. This paper proposes a multi signcryption scheme in which no pairing is computed on the signcryption stage and the signatures can be verified publicly.
متن کاملA Fast Publicly Verifiable Secret Sharing Scheme using Non-homogeneous Linear Recursions
A non-interactive (t,n)-publicly veriable secret sharing scheme (non-interactive (t,n)-PVSS scheme) is a (t,n)-secret sharing scheme in which anyone, not only the participants of the scheme, can verify the correctness of the produced shares without interacting with the dealer and participants. The (t,n)-PVSS schemes have found a lot of applications in cryptography because they are suitable for<...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- IACR Cryptology ePrint Archive
دوره 2003 شماره
صفحات -
تاریخ انتشار 2003