Documentation
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Overview ¶
Package ring implements ring signatures for anonymous group signing.
Ring signatures allow a member of a group to sign a message such that it can be verified as coming from someone in the group, but without revealing which member actually signed. This provides strong anonymity guarantees.
This package provides:
- LSAG (Linkable Spontaneous Anonymous Group) signatures using secp256k1
- Post-quantum ring signatures using lattice-based cryptography
- Key image support for linkability (double-spend prevention)
For Q-Chain, ring signatures enable private transactions where the sender's identity is hidden among a set of possible signers (the "ring").
Index ¶
- Variables
- func GenerateRing(scheme Scheme, size int) ([][]byte, error)
- func VerifyAndRecord(sig RingSignature, message []byte, ring [][]byte, store KeyImageStore) error
- type KeyImageStore
- type LSAGSignature
- type LSAGSigner
- type LatticeSignature
- type LatticeSigner
- type MemoryKeyImageStore
- type RingSignature
- type Scheme
- type Signer
Constants ¶
This section is empty.
Variables ¶
var ( // ErrInvalidRingSize is returned when the ring size is invalid. ErrInvalidRingSize = errors.New("invalid ring size: must be at least 2") // ErrInvalidSignerIndex is returned when the signer index is out of bounds. ErrInvalidSignerIndex = errors.New("signer index out of bounds") // ErrInvalidSignature is returned when signature verification fails. ErrInvalidSignature = errors.New("invalid ring signature") // ErrInvalidKeyImage is returned when the key image is invalid. ErrInvalidKeyImage = errors.New("invalid key image") // ErrKeyImageReused is returned when a key image has been used before. ErrKeyImageReused = errors.New("key image has been used (double spend detected)") // ErrInvalidPublicKey is returned when a public key is invalid. ErrInvalidPublicKey = errors.New("invalid public key") // ErrInvalidPrivateKey is returned when a private key is invalid. ErrInvalidPrivateKey = errors.New("invalid private key") // ErrRingSizeMismatch is returned when signature ring size doesn't match. ErrRingSizeMismatch = errors.New("ring size mismatch") )
Functions ¶
func GenerateRing ¶
GenerateRing generates a ring of random public keys for testing/demo purposes. In production, the ring should consist of real public keys from the network.
func VerifyAndRecord ¶
func VerifyAndRecord(sig RingSignature, message []byte, ring [][]byte, store KeyImageStore) error
VerifyAndRecord verifies a ring signature and records its key image. Returns an error if verification fails or if the key image was already used.
Types ¶
type KeyImageStore ¶
type KeyImageStore interface {
// HasKeyImage checks if a key image has been used.
HasKeyImage(keyImage []byte) bool
// AddKeyImage records a key image as used.
AddKeyImage(keyImage []byte) error
// RemoveKeyImage removes a key image (for rollback).
RemoveKeyImage(keyImage []byte) error
}
KeyImageStore tracks used key images for double-spend detection.
type LSAGSignature ¶
type LSAGSignature struct {
// contains filtered or unexported fields
}
LSAGSignature implements linkable ring signatures using secp256k1. Based on the Linkable Spontaneous Anonymous Group signature scheme.
func ParseLSAGSignature ¶
func ParseLSAGSignature(data []byte) (*LSAGSignature, error)
ParseLSAGSignature parses an LSAG signature from bytes.
func (*LSAGSignature) Bytes ¶
func (sig *LSAGSignature) Bytes() []byte
Bytes serializes the signature.
func (*LSAGSignature) KeyImage ¶
func (sig *LSAGSignature) KeyImage() []byte
KeyImage returns the key image for linkability.
func (*LSAGSignature) RingSize ¶
func (sig *LSAGSignature) RingSize() int
RingSize returns the number of public keys in the ring.
type LSAGSigner ¶
type LSAGSigner struct {
// contains filtered or unexported fields
}
LSAGSigner creates LSAG ring signatures.
func NewLSAGSigner ¶
func NewLSAGSigner(reader io.Reader) (*LSAGSigner, error)
NewLSAGSigner creates a new LSAG signer with a random private key.
func NewLSAGSignerFromPrivateKey ¶
func NewLSAGSignerFromPrivateKey(privateKey []byte) (*LSAGSigner, error)
NewLSAGSignerFromPrivateKey creates an LSAG signer from an existing private key.
func (*LSAGSigner) KeyImage ¶
func (s *LSAGSigner) KeyImage() []byte
KeyImage returns the key image.
func (*LSAGSigner) PublicKey ¶
func (s *LSAGSigner) PublicKey() []byte
PublicKey returns the signer's compressed public key.
func (*LSAGSigner) Sign ¶
func (signer *LSAGSigner) Sign(message []byte, ring [][]byte, signerIndex int) (RingSignature, error)
Sign creates a ring signature for the message.
type LatticeSignature ¶
type LatticeSignature struct {
// contains filtered or unexported fields
}
LatticeSignature implements post-quantum ring signatures. Uses ML-DSA key material with a hash-based ring construction.
func ParseLatticeSignature ¶
func ParseLatticeSignature(data []byte) (*LatticeSignature, error)
ParseLatticeSignature parses a lattice ring signature from bytes.
func (*LatticeSignature) Bytes ¶
func (sig *LatticeSignature) Bytes() []byte
Bytes serializes the signature.
func (*LatticeSignature) KeyImage ¶
func (sig *LatticeSignature) KeyImage() []byte
KeyImage returns the key image for linkability.
func (*LatticeSignature) RingSize ¶
func (sig *LatticeSignature) RingSize() int
RingSize returns the number of public keys in the ring.
func (*LatticeSignature) Scheme ¶
func (sig *LatticeSignature) Scheme() Scheme
Scheme returns LatticeLSAG.
type LatticeSigner ¶
type LatticeSigner struct {
// contains filtered or unexported fields
}
LatticeSigner creates post-quantum ring signatures using ML-DSA key material.
func NewLatticeSigner ¶
func NewLatticeSigner(reader io.Reader) (*LatticeSigner, error)
NewLatticeSigner creates a new lattice-based ring signer.
func NewLatticeSignerFromPrivateKey ¶
func NewLatticeSignerFromPrivateKey(privateKey []byte) (*LatticeSigner, error)
NewLatticeSignerFromPrivateKey creates a signer from an existing private key.
func (*LatticeSigner) KeyImage ¶
func (s *LatticeSigner) KeyImage() []byte
KeyImage returns the key image.
func (*LatticeSigner) PublicKey ¶
func (s *LatticeSigner) PublicKey() []byte
PublicKey returns the signer's public key.
func (*LatticeSigner) Sign ¶
func (signer *LatticeSigner) Sign(message []byte, ring [][]byte, signerIndex int) (RingSignature, error)
Sign creates a lattice-based ring signature.
type MemoryKeyImageStore ¶
type MemoryKeyImageStore struct {
// contains filtered or unexported fields
}
MemoryKeyImageStore is an in-memory implementation of KeyImageStore.
func NewMemoryKeyImageStore ¶
func NewMemoryKeyImageStore() *MemoryKeyImageStore
NewMemoryKeyImageStore creates a new in-memory key image store.
func (*MemoryKeyImageStore) AddKeyImage ¶
func (s *MemoryKeyImageStore) AddKeyImage(keyImage []byte) error
AddKeyImage records a key image as used.
func (*MemoryKeyImageStore) HasKeyImage ¶
func (s *MemoryKeyImageStore) HasKeyImage(keyImage []byte) bool
HasKeyImage checks if a key image has been used.
func (*MemoryKeyImageStore) RemoveKeyImage ¶
func (s *MemoryKeyImageStore) RemoveKeyImage(keyImage []byte) error
RemoveKeyImage removes a key image.
type RingSignature ¶
type RingSignature interface {
// Scheme returns the signature scheme used.
Scheme() Scheme
// Bytes serializes the signature to bytes.
Bytes() []byte
// KeyImage returns the key image for linkability.
// Two signatures from the same private key will have the same key image.
KeyImage() []byte
// RingSize returns the number of public keys in the ring.
RingSize() int
// Verify verifies the signature against the given message and ring.
Verify(message []byte, ring [][]byte) bool
}
RingSignature represents a ring signature that can be verified against a ring of public keys without revealing which key created it.
func ParseSignature ¶
func ParseSignature(scheme Scheme, data []byte) (RingSignature, error)
ParseSignature parses a ring signature from bytes.
type Scheme ¶
type Scheme int
Signature scheme types
const ( // LSAG is the Linkable Spontaneous Anonymous Group signature scheme // based on secp256k1 elliptic curves. LSAG Scheme = iota // LatticeLSAG is a post-quantum linkable ring signature scheme // based on Module-LWE lattices. LatticeLSAG // DualRing is an efficient ring signature construction. DualRing )
type Signer ¶
type Signer interface {
// Scheme returns the signature scheme used.
Scheme() Scheme
// PublicKey returns the signer's public key.
PublicKey() []byte
// Sign creates a ring signature for the given message.
// The signer's public key must be included in the ring at signerIndex.
Sign(message []byte, ring [][]byte, signerIndex int) (RingSignature, error)
// KeyImage returns the key image derived from this signer's private key.
KeyImage() []byte
}
Signer creates ring signatures.
func NewSignerFromPrivateKey ¶
NewSignerFromPrivateKey creates a signer from an existing private key.
Source Files