diff --git a/lix/libstore/build/derivation-goal.hh b/lix/libstore/build/derivation-goal.hh
index 0fa1c634b..0ca01c070 100644
--- a/lix/libstore/build/derivation-goal.hh
+++ b/lix/libstore/build/derivation-goal.hh
@@ -292,11 +292,6 @@ struct DerivationGoal : public Goal
      */
     Path openLogFile();
 
-    /**
-     * Sign the newly built realisation if the store allows it
-     */
-    virtual void signRealisation(Realisation&) {}
-
     /**
      * Close the log file.
      */
diff --git a/lix/libstore/build/local-derivation-goal.cc b/lix/libstore/build/local-derivation-goal.cc
index bb72d2c1a..28940a01c 100644
--- a/lix/libstore/build/local-derivation-goal.cc
+++ b/lix/libstore/build/local-derivation-goal.cc
@@ -2052,11 +2052,6 @@ try {
     co_return result::current_exception();
 }
 
-void LocalDerivationGoal::signRealisation(Realisation & realisation)
-{
-    getLocalStore().signRealisation(realisation);
-}
-
 
 kj::Promise<Result<void>> LocalDerivationGoal::checkOutputs(const std::map<std::string, ValidPathInfo> & newlyBuiltOutputs, const std::map<std::string, StorePath> & alreadyRegisteredOutputs)
 try {
diff --git a/lix/libstore/build/local-derivation-goal.hh b/lix/libstore/build/local-derivation-goal.hh
index 918893cd8..083ca2236 100644
--- a/lix/libstore/build/local-derivation-goal.hh
+++ b/lix/libstore/build/local-derivation-goal.hh
@@ -203,8 +203,6 @@ struct LocalDerivationGoal : public DerivationGoal
      */
     kj::Promise<Result<SingleDrvOutputs>> registerOutputs() override;
 
-    void signRealisation(Realisation &) override;
-
     /**
      * Check that an output meets the requirements specified by the
      * 'outputChecks' attribute (or the legacy
diff --git a/lix/libstore/local-store.cc b/lix/libstore/local-store.cc
index 96b59c22f..287f9a932 100644
--- a/lix/libstore/local-store.cc
+++ b/lix/libstore/local-store.cc
@@ -1225,11 +1225,6 @@ bool LocalStore::pathInfoIsUntrusted(const ValidPathInfo & info)
     return config_.requireSigs && !info.checkSignatures(*this, getPublicKeys());
 }
 
-bool LocalStore::realisationIsUntrusted(const Realisation & realisation)
-{
-    return config_.requireSigs && !realisation.checkSignatures(getPublicKeys());
-}
-
 kj::Promise<Result<void>> LocalStore::addToStore(
     const ValidPathInfo & info,
     AsyncInputStream & source,
@@ -1816,18 +1811,6 @@ try {
 }
 
 
-void LocalStore::signRealisation(Realisation & realisation)
-{
-    // FIXME: keep secret keys in memory.
-
-    auto secretKeyFiles = settings.secretKeyFiles;
-
-    for (auto & secretKeyFile : secretKeyFiles.get()) {
-        SecretKey secretKey(readFile(secretKeyFile));
-        realisation.sign(secretKey);
-    }
-}
-
 void LocalStore::signPathInfo(ValidPathInfo & info)
 {
     // FIXME: keep secret keys in memory.
diff --git a/lix/libstore/local-store.hh b/lix/libstore/local-store.hh
index 07bf7e7d6..c76d49c4e 100644
--- a/lix/libstore/local-store.hh
+++ b/lix/libstore/local-store.hh
@@ -210,7 +210,6 @@ public:
     kj::Promise<Result<StorePathSet>> querySubstitutablePaths(const StorePathSet & paths) override;
 
     bool pathInfoIsUntrusted(const ValidPathInfo &) override;
-    bool realisationIsUntrusted(const Realisation & ) override;
 
     kj::Promise<Result<void>> addToStore(const ValidPathInfo & info, AsyncInputStream & source,
         RepairFlag repair, CheckSigsFlag checkSigs) override;
@@ -392,7 +391,6 @@ private:
      * specified by the ‘secret-key-files’ option.
      */
     void signPathInfo(ValidPathInfo & info);
-    void signRealisation(Realisation &);
 
     // XXX: Make a generic `Store` method
     ContentAddress hashCAPath(
diff --git a/lix/libstore/realisation.cc b/lix/libstore/realisation.cc
index 0592bb89d..e4a7bf0db 100644
--- a/lix/libstore/realisation.cc
+++ b/lix/libstore/realisation.cc
@@ -71,36 +71,6 @@ Realisation Realisation::fromJSON(
     };
 }
 
-std::string Realisation::fingerprint() const
-{
-    auto serialized = toJSON();
-    serialized.erase("signatures");
-    return serialized.dump();
-}
-
-void Realisation::sign(const SecretKey & secretKey)
-{
-    signatures.insert(secretKey.signDetached(fingerprint()));
-}
-
-bool Realisation::checkSignature(const PublicKeys & publicKeys, const std::string & sig) const
-{
-    return verifyDetached(fingerprint(), sig, publicKeys);
-}
-
-size_t Realisation::checkSignatures(const PublicKeys & publicKeys) const
-{
-    // FIXME: Maybe we should return `maxSigs` if the realisation corresponds to
-    // an input-addressed one − because in that case the drv is enough to check
-    // it − but we can't know that here.
-
-    size_t good = 0;
-    for (auto & sig : signatures)
-        if (checkSignature(publicKeys, sig))
-            good++;
-    return good;
-}
-
 
 SingleDrvOutputs filterDrvOutputs(const OutputsSpec& wanted, SingleDrvOutputs&& outputs)
 {
@@ -118,24 +88,6 @@ StorePath RealisedPath::path() const {
     return std::visit([](auto && arg) { return arg.getPath(); }, raw);
 }
 
-bool Realisation::isCompatibleWith(const Realisation & other) const
-{
-    assert (id == other.id);
-    if (outPath == other.outPath) {
-        if (dependentRealisations.empty() != other.dependentRealisations.empty()) {
-            warn(
-                "Encountered a realisation for '%s' with an empty set of "
-                "dependencies. This is likely an artifact from an older Nix. "
-                "I’ll try to fix the realisation if I can",
-                id.to_string());
-            return true;
-        } else if (dependentRealisations == other.dependentRealisations) {
-            return true;
-        }
-    }
-    return false;
-}
-
 kj::Promise<Result<void>> RealisedPath::closure(
     Store& store,
     const RealisedPath::Set& startPaths,
diff --git a/lix/libstore/realisation.hh b/lix/libstore/realisation.hh
index 17c9008ca..f263c6494 100644
--- a/lix/libstore/realisation.hh
+++ b/lix/libstore/realisation.hh
@@ -63,13 +63,6 @@ struct Realisation {
     JSON toJSON() const;
     static Realisation fromJSON(const JSON& json, const std::string& whence);
 
-    std::string fingerprint() const;
-    void sign(const SecretKey &);
-    bool checkSignature(const PublicKeys & publicKeys, const std::string & sig) const;
-    size_t checkSignatures(const PublicKeys & publicKeys) const;
-
-    bool isCompatibleWith(const Realisation & other) const;
-
     StorePath getPath() const { return outPath; }
 
     GENERATE_CMP(Realisation, me->id, me->outPath);
diff --git a/lix/libstore/store-api.hh b/lix/libstore/store-api.hh
index 39ee68d7f..07cdf68f8 100644
--- a/lix/libstore/store-api.hh
+++ b/lix/libstore/store-api.hh
@@ -409,11 +409,6 @@ public:
         return true;
     }
 
-    virtual bool realisationIsUntrusted(const Realisation & )
-    {
-        return true;
-    }
-
 protected:
 
     /**