Identity-Based Aggregate Signature Scheme for Bandwidth Efficiency
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Solution Overview
Problem
Current digital signature schemes are not bandwidth-efficient, as they require a significant amount of information to verify, including large public keys and document descriptions, which does not minimize the total information needed for verification, especially in aggregate signature schemes where the size of the aggregate signature grows with the number of signers.
Innovation Solution
The development of identity-based aggregate signature schemes where signers' public identities act as their public keys, generated by a Private Key Generator, allowing for flexible aggregation of signatures without dependence on the number of signers, using bilinear maps and cryptographic hash functions to create a compact and secure verification process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional digital signature schemes are used, then security is maintained, but bandwidth efficiency deteriorates due to large public keys and document descriptions required for verification
Solution Approach 1:
The patent merges multiple individual signatures into a single aggregate signature that represents multiple signers. The aggregate signature scheme combines signatures from multiple signers on different documents into one compact signature, eliminating the need to transmit and verify separate public keys and document descriptions for each signer. This merging reduces the total information size required for verification while maintaining the security properties of individual signatures.
Solution Approach 2:
The patent implements identity-based signatures where a single public key (the identity) serves multiple functions: it acts as the verification key for signature verification and also uniquely identifies the signer. This universal identity-based approach eliminates the need for separate public keys for each signer in aggregate signatures, further reducing the information size required for verification while maintaining security.
2Quantity of substance
If aggregate signature schemes are used to reduce verification information, then bandwidth efficiency improves, but the size of the aggregate signature grows with the number of signers
Solution Approach 1:
The patent merges multiple identities and their corresponding signatures into a single aggregate signature structure. The mathematical formulation combines all individual signature components into one aggregate signature that does not linearly grow with the number of signers. The verification process uses a single aggregate public key derivation that efficiently handles any number of signers without proportionally increasing the signature size or verification complexity.
Solution Approach 2:
The patent changes the fundamental parameters of the signature scheme by using identity-based cryptography where the public key is derived from the signer's identity through a hash function. This parameter change allows the aggregate signature to remain compact regardless of the number of signers, as the verification process relies on the aggregate identity derivation rather than individual public keys for each signer.
3Measurement precision
If individual public keys are used for each signer, then verification accuracy is maintained, but bandwidth efficiency deteriorates
Solution Approach 1:
The patent makes the identity universal by using it both as the public verification key and as the unique identifier for the signer. This eliminates the need to transmit separate public keys for verification, as the identity itself serves this purpose. The verification accuracy is maintained because the identity-based verification process cryptographically ensures that only the holder of the corresponding private key could have produced a valid signature on that identity.
Solution Approach 2:
The patent extracts the public key information from the signature transmission by deriving it from the signer's identity. Instead of including individual public keys in the verification data, the system extracts or derives the verification key from the identity string through a deterministic process, thereby removing redundant information transmission while preserving verification accuracy.
Data Source
AI summary
Methods and systems are provided that allow multiple identity-based digital signatures to be merged into a single identity-based “aggregate” digital signature. This identity-based aggregate signature has a shorter bit-length than the concatenation of the original unaggregated identity-based signatures. The identity-based aggregate signature can be verified by anyone who obtains the public keys of one or more Private Key Generators (PKGs), along with a description of which signer signed which message. The verifier does not need to obtain a different public key for each signer, since the signature scheme is “identity-based”; the number of PKGs may be fewer than the number of signers. Consequently, the total information needed to verify the identity-based aggregate signature—namely, a description of who signed what, the PKGs' public keys, and the identity-based aggregate signature itself—may be less than the information needed to verify separate digital signatures—namely, a description of who signed what, the public verification keys for all of the signers, and the concatenation of the signers' signatures. In some embodiments, the identity-based aggregate signature scheme has essentially the minimum-possible Kolmogorov complexity.