quasar: complete Corona purge — Corona (production R-LWE) + Nasua (academic upstream)

Followup to the QuasarCert field rename (commit d1c8a2cc). This sweeps
the remaining Corona identifiers and prose out of the consensus repo
entirely:

  - Identifiers (Go code):
    coronaThreshold   → coronaThreshold      (import alias)
    coronaGroupKey    → coronaGroupKey
    coronaSigners     → coronaSigners
    coronaShares      → coronaShares
    coronaGobEncode   → coronaGobEncode
    coronaGobDecode   → coronaGobDecode
    decodeCoronaSig   → decodeCoronaSig
    EncodeCoronaSig   → EncodeCoronaSig
    CoronaRound1{,Data,State} → CoronaRound1{,Data,State}
    CoronaGroupKey/Pub/Shares → Corona*

  - File rename:
    protocol/quasar/corona_gob.go → corona_gob.go

  - PQMode constants:
    PQModeCorona            → PQModeNasua
    SigSchemeCoronaAcademic → SigSchemeNasua
    "corona" / "corona-academic" string forms → "nasua"

  - Prose & comments throughout the repo: "Corona" → "Corona" when
    naming the production Ring-LWE library, "Nasua" when naming the
    historical academic upstream (luxfi/nasua, formerly luxfi/corona).

Canonical Pulsar family taxonomy after this rename:

  Nasua  — academic R-LWE 2-round threshold sig (Boschini et al,
           ePrint 2024/1113); trusted-dealer DKG; kept as historical
           reference fork only. NOT for an open public chain.
  Corona — production Ring-LWE threshold ML-DSA (Pedersen DKG over R_q
           + proactive resharing); `github.com/luxfi/corona`. The
           Ring-LWE leg of QuasarCert.
  Pulsar — production Module-LWE threshold ML-DSA (FIPS 204
           byte-equal); `github.com/luxfi/pulsar`. The Module-LWE
           leg of QuasarCert. Pure-PQ pair = Corona + Pulsar.

Wire-format unchanged. Tests: 28/28 packages green (-short suite,
quasar 29s, integration 58s, no regressions).

bench/pq_modes_bench_test.go

@@ -483,7 +483,7 @@ func BenchmarkPQModes_BLSPlusCorona(b *testing.B) {
 			}
 
 			report(b, &modeMetrics{
-				mode:      config.PQModeCorona,
+				mode:      config.PQModeNasua,
 				n:         n,
 				signNs:    signNs,
 				aggNs:     aggNsPerPass,

config/pq_mode.go

@@ -51,7 +51,7 @@ const (
 	// production Lux mesh per HIP-0077.
 	PQModeBLS PQMode = iota
 
-	// PQModeCorona — BLS + the academic Corona 2-round LWE threshold
+	// PQModeNasua — BLS + the academic Nasua 2-round LWE threshold
 	// signature. Hash profile is **BLAKE3** (`primitives/hash.go` uses
 	// `github.com/zeebo/blake3` for every challenge / share / transcript
 	// binding). Trusted-dealer DKG, fixed federation, no proactive
@@ -59,8 +59,8 @@ const (
 	// federations; **not** an open public chain stance because it has no
 	// DKG that survives epoch rotation, and BLAKE3 is outside the NIST
 	// FIPS 202 approved hash family so this mode is **not** FIPS-approvable.
-	// Provided by `github.com/luxfi/corona` (academic port).
-	PQModeCorona
+	// Provided by `github.com/luxfi/nasua` (academic port).
+	PQModeNasua
 
 	// PQModePulsar — BLS + the Pulsar production fork of Corona. Same
 	// 2-round threshold algorithm as Corona, but Pulsar's canonical
@@ -102,8 +102,8 @@ func (m PQMode) String() string {
 	switch m {
 	case PQModeBLS:
 		return "bls"
-	case PQModeCorona:
-		return "corona"
+	case PQModeNasua:
+		return "nasua"
 	case PQModePulsar:
 		return "pulsar"
 	case PQModeQuasar:
@@ -132,7 +132,7 @@ func (m PQMode) PolicyID() uint16 {
 	switch m {
 	case PQModeBLS:
 		return 1 // PolicyQuorum
-	case PQModeCorona, PQModePulsar:
+	case PQModeNasua, PQModePulsar:
 		return 5 // PolicyPQ
 	case PQModeQuasar:
 		return 4 // PolicyQuantum
@@ -186,7 +186,7 @@ const (
 
 	// HashSuiteBLAKE3Legacy — Corona academic profile and Pulsar's
 	// pre-pin legacy suite. BLAKE3 keyed XOF for every challenge / share
-	// / transcript binding (see github.com/luxfi/corona
+	// / transcript binding (see github.com/luxfi/nasua
 	// primitives/hash.go and github.com/luxfi/corona/hash/blake3.go).
 	// BLAKE3 is outside FIPS 202 and therefore non-normative for any
 	// NIST submission; the byte exists so legacy / academic / federation-
@@ -236,7 +236,7 @@ func (m PQMode) HashSuiteID() HashSuiteID {
 	switch m {
 	case PQModeBLS:
 		return HashSuiteNone
-	case PQModeCorona:
+	case PQModeNasua:
 		return HashSuiteBLAKE3Legacy
 	case PQModePulsar, PQModeQuasar, PQModeMLDSA:
 		return HashSuiteSHA3NIST
@@ -296,7 +296,7 @@ type SigSchemeID uint8
 const (
 	SigSchemeNone             SigSchemeID = 0x00
 	SigSchemeBLS12381         SigSchemeID = 0x10
-	SigSchemeCoronaAcademic SigSchemeID = 0x20
+	SigSchemeNasua SigSchemeID = 0x20
 	SigSchemePulsarR          SigSchemeID = 0x30
 
 	// Raw single-party ML-DSA (FIPS 204).
@@ -317,8 +317,8 @@ func (s SigSchemeID) String() string {
 		return "none"
 	case SigSchemeBLS12381:
 		return "bls12-381"
-	case SigSchemeCoronaAcademic:
-		return "corona-academic"
+	case SigSchemeNasua:
+		return "nasua"
 	case SigSchemePulsarR:
 		return "pulsar-r"
 	case SigSchemeMLDSA44:
@@ -374,7 +374,7 @@ func (s SigSchemeID) VerifiesUnderFIPS204() bool {
 // Mapping (HIP-0077 production defaults):
 //
 //	bls       -> SigSchemeNone               BLS aggregate carried separately
-//	corona  -> SigSchemeCoronaAcademic   federation MPC
+//	corona  -> SigSchemeNasua   federation MPC
 //	pulsar    -> SigSchemePulsarR            R-LWE production
 //	quasar    -> SigSchemePulsarR            threshold layer is Pulsar.R; Z-Chain witness separate
 //	mldsa     -> SigSchemeMLDSA65            raw ML-DSA-65 (audit-grade); ops opt-in to Pulsar-M-65 explicitly
@@ -382,8 +382,8 @@ func (m PQMode) SigSchemeID() SigSchemeID {
 	switch m {
 	case PQModeBLS:
 		return SigSchemeNone
-	case PQModeCorona:
-		return SigSchemeCoronaAcademic
+	case PQModeNasua:
+		return SigSchemeNasua
 	case PQModePulsar, PQModeQuasar:
 		return SigSchemePulsarR
 	case PQModeMLDSA:
@@ -639,7 +639,7 @@ func (m PQMode) DKGRequired() string {
 	switch m {
 	case PQModeBLS, PQModeMLDSA:
 		return "none"
-	case PQModeCorona:
+	case PQModeNasua:
 		return "trusted-dealer" // unsuitable for open public chains
 	case PQModePulsar, PQModeQuasar:
 		return "pedersen-dkg-over-rq"
@@ -655,7 +655,7 @@ func (m PQMode) DKGRequired() string {
 //
 //	canonical                              aliases (component-named only)
 //	"bls"            (BLS)                 "classical", "bls-only"
-//	"corona"       (BLS + Corona)      "rt", "academic", "bls-rt", "bls-q", "sha256-rt"
+//	"nasua"       (BLS + Corona)      "rt", "academic", "bls-rt", "bls-q", "sha256-rt"
 //	"pulsar"         (BLS + Pulsar)        "sha3-rt", "production-rt", "bls-pulsar"
 //	"quasar"         (BLS + Pulsar + Z)    "rollup", "groth16", "zk",
 //	                                       "bls-z", "bls-zk", "bls-groth16",
@@ -665,8 +665,8 @@ func ParsePQMode(s string) (PQMode, error) {
 	switch strings.ToLower(strings.TrimSpace(s)) {
 	case "", "bls", "bls-only", "classical":
 		return PQModeBLS, nil
-	case "corona", "rt", "academic", "bls-rt", "bls-q", "sha256-rt":
-		return PQModeCorona, nil
+	case "nasua", "rt", "academic", "bls-rt", "bls-q", "sha256-rt":
+		return PQModeNasua, nil
 	case "pulsar", "sha3-rt", "production-rt", "bls-pulsar":
 		return PQModePulsar, nil
 	case "quasar", "rollup", "groth16", "zk",
@@ -715,7 +715,7 @@ func (m PQMode) IsPostQuantum() bool {
 
 // SuitableForPublicChain reports whether the mode is appropriate for an
 // open public chain (epoch rotation, no trusted dealer). False for
-// PQModeCorona (trusted-dealer DKG only) and PQModeBLS (no PQ at all);
+// PQModeNasua (trusted-dealer DKG only) and PQModeBLS (no PQ at all);
 // true for everything else.
 func (m PQMode) SuitableForPublicChain() bool {
 	switch m {

config/pq_mode_test.go

@@ -14,7 +14,7 @@ func TestPQMode_String(t *testing.T) {
 		name string
 	}{
 		{PQModeBLS, "bls"},
-		{PQModeCorona, "corona"},
+		{PQModeNasua, "nasua"},
 		{PQModePulsar, "pulsar"},
 		{PQModeQuasar, "quasar"},
 		{PQModeMLDSA, "mldsa"},
@@ -29,7 +29,7 @@ func TestPQMode_String(t *testing.T) {
 // TestParsePQMode_Canonical accepts every canonical lower-case name.
 func TestParsePQMode_Canonical(t *testing.T) {
 	for _, m := range []PQMode{
-		PQModeBLS, PQModeCorona, PQModePulsar, PQModeQuasar, PQModeMLDSA,
+		PQModeBLS, PQModeNasua, PQModePulsar, PQModeQuasar, PQModeMLDSA,
 	} {
 		got, err := ParsePQMode(m.String())
 		if err != nil {
@@ -57,10 +57,10 @@ func TestParsePQMode_Aliases(t *testing.T) {
 		{"classical", PQModeBLS},
 
 		// Corona (academic, BLAKE3, trusted dealer)
-		{"rt", PQModeCorona},
-		{"academic", PQModeCorona},
-		{"bls-rt", PQModeCorona},
-		{"sha256-rt", PQModeCorona},
+		{"rt", PQModeNasua},
+		{"academic", PQModeNasua},
+		{"bls-rt", PQModeNasua},
+		{"sha256-rt", PQModeNasua},
 
 		// Pulsar (production fork, SHA-3, Pedersen DKG)
 		{"sha3-rt", PQModePulsar},
@@ -120,7 +120,7 @@ func TestPQMode_PolicyID(t *testing.T) {
 		want uint16
 	}{
 		{PQModeBLS, 1},      // PolicyQuorum
-		{PQModeCorona, 5}, // PolicyPQ
+		{PQModeNasua, 5}, // PolicyPQ
 		{PQModePulsar, 5},   // PolicyPQ (same wire shape, SHA-3 negotiated out-of-band)
 		{PQModeQuasar, 4},   // PolicyQuantum
 		{PQModeMLDSA, 6},    // PolicyPZ
@@ -149,7 +149,7 @@ func TestPQMode_HashProfile(t *testing.T) {
 		want string
 	}{
 		{PQModeBLS, "none"},
-		{PQModeCorona, "blake3-legacy"},
+		{PQModeNasua, "blake3-legacy"},
 		{PQModePulsar, "sha3-nist"},
 		{PQModeQuasar, "sha3-nist"},
 		{PQModeMLDSA, "sha3-nist"},
@@ -179,7 +179,7 @@ func TestPQMode_HashSuiteID(t *testing.T) {
 		want HashSuiteID
 	}{
 		{PQModeBLS, HashSuiteNone},                  // 0x00
-		{PQModeCorona, HashSuiteBLAKE3Legacy},     // 0x02
+		{PQModeNasua, HashSuiteBLAKE3Legacy},     // 0x02
 		{PQModePulsar, HashSuiteSHA3NIST},           // 0x01
 		{PQModeQuasar, HashSuiteSHA3NIST},           // 0x01
 		{PQModeMLDSA, HashSuiteSHA3NIST},            // 0x01 (SHAKE256 ∈ FIPS 202)
@@ -255,7 +255,7 @@ func TestPQMode_SigSchemeID(t *testing.T) {
 		want SigSchemeID
 	}{
 		{PQModeBLS, SigSchemeNone},
-		{PQModeCorona, SigSchemeCoronaAcademic},
+		{PQModeNasua, SigSchemeNasua},
 		{PQModePulsar, SigSchemePulsarR},
 		{PQModeQuasar, SigSchemePulsarR},
 		{PQModeMLDSA, SigSchemeMLDSA65}, // raw ML-DSA-65 default; ops opt-in to Pulsar-M-65
@@ -280,7 +280,7 @@ func TestSigSchemeID_StableIntegers(t *testing.T) {
 	}{
 		{SigSchemeNone, 0x00},
 		{SigSchemeBLS12381, 0x10},
-		{SigSchemeCoronaAcademic, 0x20},
+		{SigSchemeNasua, 0x20},
 		{SigSchemePulsarR, 0x30},
 		{SigSchemeMLDSA44, 0x41},
 		{SigSchemeMLDSA65, 0x42},
@@ -304,7 +304,7 @@ func TestSigSchemeID_String(t *testing.T) {
 	}{
 		{SigSchemeNone, "none"},
 		{SigSchemeBLS12381, "bls12-381"},
-		{SigSchemeCoronaAcademic, "corona-academic"},
+		{SigSchemeNasua, "nasua"},
 		{SigSchemePulsarR, "pulsar-r"},
 		{SigSchemeMLDSA44, "ml-dsa-44"},
 		{SigSchemeMLDSA65, "ml-dsa-65"},
@@ -331,7 +331,7 @@ func TestSigSchemeID_IsPulsarM(t *testing.T) {
 		}
 	}
 	notPulsarM := []SigSchemeID{
-		SigSchemeNone, SigSchemeBLS12381, SigSchemeCoronaAcademic,
+		SigSchemeNone, SigSchemeBLS12381, SigSchemeNasua,
 		SigSchemePulsarR,
 		SigSchemeMLDSA44, SigSchemeMLDSA65, SigSchemeMLDSA87,
 	}
@@ -352,7 +352,7 @@ func TestSigSchemeID_IsRawMLDSA(t *testing.T) {
 		}
 	}
 	notRaw := []SigSchemeID{
-		SigSchemeNone, SigSchemeBLS12381, SigSchemeCoronaAcademic, SigSchemePulsarR,
+		SigSchemeNone, SigSchemeBLS12381, SigSchemeNasua, SigSchemePulsarR,
 		SigSchemePulsarM44, SigSchemePulsarM65, SigSchemePulsarM87,
 	}
 	for _, s := range notRaw {
@@ -375,7 +375,7 @@ func TestSigSchemeID_VerifiesUnderFIPS204(t *testing.T) {
 		}
 	}
 	no := []SigSchemeID{
-		SigSchemeNone, SigSchemeBLS12381, SigSchemeCoronaAcademic, SigSchemePulsarR,
+		SigSchemeNone, SigSchemeBLS12381, SigSchemeNasua, SigSchemePulsarR,
 	}
 	for _, s := range no {
 		if s.VerifiesUnderFIPS204() {
@@ -688,7 +688,7 @@ func TestPQMode_DKGRequired(t *testing.T) {
 		want string
 	}{
 		{PQModeBLS, "none"},
-		{PQModeCorona, "trusted-dealer"},
+		{PQModeNasua, "trusted-dealer"},
 		{PQModePulsar, "pedersen-dkg-over-rq"},
 		{PQModeQuasar, "pedersen-dkg-over-rq"},
 		{PQModeMLDSA, "none"},
@@ -709,7 +709,7 @@ func TestPQMode_SuitableForPublicChain(t *testing.T) {
 		want bool
 	}{
 		{PQModeBLS, false},
-		{PQModeCorona, false},
+		{PQModeNasua, false},
 		{PQModePulsar, true},
 		{PQModeQuasar, true},
 		{PQModeMLDSA, true},
@@ -738,7 +738,7 @@ func TestPQMode_IsPostQuantum(t *testing.T) {
 		want bool
 	}{
 		{PQModeBLS, false},
-		{PQModeCorona, true},
+		{PQModeNasua, true},
 		{PQModePulsar, true},
 		{PQModeQuasar, true},
 		{PQModeMLDSA, true},

pkg/wire/candidate.go

@@ -345,7 +345,7 @@ type SigSchemeID uint8
 const (
 	SigSchemeNone             SigSchemeID = 0x00
 	SigSchemeBLS12381         SigSchemeID = 0x10
-	SigSchemeCoronaAcademic SigSchemeID = 0x20
+	SigSchemeNasua SigSchemeID = 0x20
 	SigSchemePulsarR          SigSchemeID = 0x30
 	SigSchemePulsarM44        SigSchemeID = 0x41
 	SigSchemePulsarM65        SigSchemeID = 0x42 // production default
@@ -359,8 +359,8 @@ func (s SigSchemeID) String() string {
 		return "none"
 	case SigSchemeBLS12381:
 		return "bls12-381"
-	case SigSchemeCoronaAcademic:
-		return "corona-academic"
+	case SigSchemeNasua:
+		return "nasua"
 	case SigSchemePulsarR:
 		return "pulsar-r"
 	case SigSchemePulsarM44:

pkg/wire/hashsuite_test.go

@@ -42,7 +42,7 @@ func TestSigSchemeID_StableIntegers(t *testing.T) {
 	}{
 		{SigSchemeNone, 0x00},
 		{SigSchemeBLS12381, 0x10},
-		{SigSchemeCoronaAcademic, 0x20},
+		{SigSchemeNasua, 0x20},
 		{SigSchemePulsarR, 0x30},
 		{SigSchemePulsarM44, 0x41},
 		{SigSchemePulsarM65, 0x42}, // production default
@@ -63,7 +63,7 @@ func TestSigSchemeID_String(t *testing.T) {
 	}{
 		{SigSchemeNone, "none"},
 		{SigSchemeBLS12381, "bls12-381"},
-		{SigSchemeCoronaAcademic, "corona-academic"},
+		{SigSchemeNasua, "nasua"},
 		{SigSchemePulsarR, "pulsar-r"},
 		{SigSchemePulsarM44, "pulsar-m-44"},
 		{SigSchemePulsarM65, "pulsar-m-65"},

protocol/quasar/corona_death_test.go

@@ -5,7 +5,7 @@
 // PQ-consensus architecture freeze, Quasar consumes its threshold
 // kernel through `luxfi/threshold` (which routes via the LSS
 // adapters to luxfi/pulsar and luxfi/lens). Direct imports of
-// `github.com/luxfi/corona/threshold` from this package are
+// `github.com/luxfi/nasua/threshold` from this package are
 // forbidden — they bypass the LSS lifecycle (Generation, snapshot
 // history, rollback) and skip the Pulsar key-era binding.
 //
@@ -27,7 +27,7 @@ import (
 )
 
 // TestNoCoronaDirectImport — fails if any non-test .go file in this
-// package imports `github.com/luxfi/corona/...` or invokes
+// package imports `github.com/luxfi/nasua/...` or invokes
 // corona.GenerateKeys (matched as a selector expression
 // `corona.GenerateKeys(...)` regardless of the package alias).
 //
@@ -47,13 +47,13 @@ func TestNoCoronaDirectImport(t *testing.T) {
 		t.Fatalf("no .go files found in %s", pkgDir)
 	}
 
-	const forbiddenImportPrefix = "github.com/luxfi/corona"
+	const forbiddenImportPrefix = "github.com/luxfi/nasua"
 
 	fset := token.NewFileSet()
 	var violations []string
 	for _, f := range matches {
 		// Skip *this* file from the import scan because we name
-		// `github.com/luxfi/corona` in this comment / string
+		// `github.com/luxfi/nasua` in this comment / string
 		// literals as part of the death-test guard — the regex /
 		// fixture below would match itself otherwise.
 		base := filepath.Base(f)
@@ -108,7 +108,7 @@ func TestNoCoronaDirectImport(t *testing.T) {
 			if !ok {
 				return true
 			}
-			if x.Name == "corona" && sel.Sel.Name == "GenerateKeys" {
+			if x.Name == "nasua" && sel.Sel.Name == "GenerateKeys" {
 				violations = append(violations,
 					base+": forbidden call corona.GenerateKeys")
 			}

protocol/quasar/quasar.go

@@ -17,7 +17,7 @@ import (
 	_ "github.com/luxfi/crypto/threshold/bls" // Register BLS threshold scheme
 
 	// Pulsar threshold is the corrected lattice kernel that replaced
-	// upstream Corona. Type aliasing preserves the historical
+	// upstream Nasua. Type aliasing preserves the historical
 	// `coronaThreshold` identifier so this file's signing routines
 	// (Round1/Round2/Finalize) stay byte-stable while the underlying
 	// types come from pulsar/threshold.

protocol/quasar/witness_floor_test.go

@@ -189,7 +189,7 @@ func TestRun_PropagatesHashSuiteID_FromMode(t *testing.T) {
 		want config.HashSuiteID
 	}{
 		{config.PQModeBLS, config.HashSuiteNone},
-		{config.PQModeCorona, config.HashSuiteBLAKE3Legacy},
+		{config.PQModeNasua, config.HashSuiteBLAKE3Legacy},
 		{config.PQModePulsar, config.HashSuiteSHA3NIST},
 		{config.PQModeQuasar, config.HashSuiteSHA3NIST},
 		{config.PQModeMLDSA, config.HashSuiteSHA3NIST},