@@ -86,6 +86,15 @@ public void serialize(Boolean value, JsonGenerator gen, SerializerProvider seria
     protected boolean usePythonSrcRootInImports = Boolean.FALSE;
     protected boolean moveTestsUnderPythonSrcRoot = Boolean.FALSE;
 
+    // Python function name suffix per security scheme name (e.g. "api-key" -> "api_key").
+    // Suffixes are assigned by addSecurityExtensions (called from preprocessOpenAPI):
+    // scheme names that are already valid identifier parts keep their name, the rest are
+    // numbered in spec order, so that the x-*Func references written into the spec and the
+    // function definitions emitted by security_controller.mustache always agree, even when
+    // the scheme name is not a valid Python identifier. fromSecurity only reads the values
+    // that addSecurityExtensions has already computed.
+    private final Map<String, String> securityFunctionNameSuffixes = new HashMap<>();
+
     public AbstractPythonConnexionServerCodegen(String templateDirectory, boolean fixBodyNameValue) {
         super();
 
@@ -459,26 +468,38 @@ private void addSecurityExtensions(OpenAPI openAPI) {
         Components components = openAPI.getComponents();
         if (components != null && components.getSecuritySchemes() != null) {
             Map<String, SecurityScheme> securitySchemes = components.getSecuritySchemes();
+            securityFunctionNameSuffixes.clear();
+            // Reserve the suffix of names that already are valid identifier parts (no
+            // character replacement needed) so they keep the same function name as before.
+            // The remaining names are numbered afterwards, in spec order, avoiding the
+            // reserved suffixes (e.g. "api-key" listed before "api_key" gets "api_key_2",
+            // while "api_key" keeps "api_key").
+            for (String securityName : securitySchemes.keySet()) {
+                if (toPythonIdentifierSuffix(securityName).equals(securityName)) {
+                    securityFunctionNameSuffixes.put(securityName, securityName);
+                }
+            }
             for (Map.Entry<String, SecurityScheme> securitySchemesEntry : securitySchemes.entrySet()) {
                 String securityName = securitySchemesEntry.getKey();
                 SecurityScheme securityScheme = securitySchemesEntry.getValue();
+                String functionSuffix = securityFunctionNameSuffix(securityName);
                 String baseFunctionName = controllerPackage + ".security_controller.";
                 switch (securityScheme.getType()) {
                     case APIKEY:
-                        addSecurityExtension(securityScheme, "x-apikeyInfoFunc", baseFunctionName + "info_from_" + securityName);
+                        addSecurityExtension(securityScheme, "x-apikeyInfoFunc", baseFunctionName + "info_from_" + functionSuffix);
                         break;
                     case HTTP:
                         if ("basic".equals(securityScheme.getScheme())) {
-                            addSecurityExtension(securityScheme, "x-basicInfoFunc", baseFunctionName + "info_from_" + securityName);
+                            addSecurityExtension(securityScheme, "x-basicInfoFunc", baseFunctionName + "info_from_" + functionSuffix);
                         } else if ("bearer".equals(securityScheme.getScheme())) {
-                            addSecurityExtension(securityScheme, "x-bearerInfoFunc", baseFunctionName + "info_from_" + securityName);
+                            addSecurityExtension(securityScheme, "x-bearerInfoFunc", baseFunctionName + "info_from_" + functionSuffix);
                         }
                         break;
                     case OPENIDCONNECT:
                         LOGGER.warn("Security type {} is not supported by connexion yet", securityScheme.getType().toString());
                     case OAUTH2:
-                        addSecurityExtension(securityScheme, "x-tokenInfoFunc", baseFunctionName + "info_from_" + securityName);
-                        addSecurityExtension(securityScheme, "x-scopeValidateFunc", baseFunctionName + "validate_scope_" + securityName);
+                        addSecurityExtension(securityScheme, "x-tokenInfoFunc", baseFunctionName + "info_from_" + functionSuffix);
+                        addSecurityExtension(securityScheme, "x-scopeValidateFunc", baseFunctionName + "validate_scope_" + functionSuffix);
                         break;
                     default:
                         LOGGER.warn("Unknown security type {}", securityScheme.getType().toString());
@@ -487,6 +508,52 @@ private void addSecurityExtensions(OpenAPI openAPI) {
         }
     }
 
+    @Override
+    public List<CodegenSecurity> fromSecurity(Map<String, SecurityScheme> schemes) {
+        List<CodegenSecurity> codegenSecurities = super.fromSecurity(schemes);
+        for (CodegenSecurity codegenSecurity : codegenSecurities) {
+            codegenSecurity.vendorExtensions.put("x-python-connexion-security-function-suffix",
+                    securityFunctionNameSuffix(codegenSecurity.name));
+        }
+        return codegenSecurities;
+    }
+
+    /**
+     * Returns the Python identifier suffix used for the info_from_/validate_scope_ functions
+     * of the given security scheme name. The result is stable per scheme name and unique across
+     * schemes of the same spec. Scheme names that already are valid identifier parts are
+     * reserved by addSecurityExtensions and keep their name; for the others, if the sanitized
+     * suffix is already taken by another scheme name (e.g. "api-key" vs "api.key"), "_2",
+     * "_3", ... is appended in spec order.
+     */
+    private String securityFunctionNameSuffix(String schemeName) {
+        return securityFunctionNameSuffixes.computeIfAbsent(schemeName, name -> {
+            String base = toPythonIdentifierSuffix(name);
+            String suffix = base;
+            for (int i = 2; securityFunctionNameSuffixes.containsValue(suffix); i++) {
+                suffix = base + "_" + i;
+            }
+            return suffix;
+        });
+    }
+
+    /**
+     * Maps a security scheme name to a string usable as part of a Python identifier:
+     * every character that is not ASCII alphanumeric or '_' becomes '_'. The result is
+     * only used after the "info_from_"/"validate_scope_" prefixes, so a leading digit
+     * needs no further fix-up.
+     */
+    private static String toPythonIdentifierSuffix(String name) {
+        StringBuilder suffix = new StringBuilder(name.length());
+        for (int i = 0; i < name.length(); i++) {
+            char c = name.charAt(i);
+            boolean isIdentifierChar = (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')
+                    || (c >= '0' && c <= '9') || c == '_';
+            suffix.append(isIdentifierChar ? c : '_');
+        }
+        return suffix.toString();
+    }
+
     private static List<OperationMap> getOperations(Map<String, Object> objs) {
         List<OperationMap> result = new ArrayList<>();
         ApiInfoMap apiInfo = (ApiInfoMap) objs.get("apiInfo");
 
@@ -3,7 +3,7 @@ from typing import List
 {{#authMethods}}
 {{#isOAuth}}
 
-def info_from_{{name}}(token: str) -> dict:
+def info_from_{{{vendorExtensions.x-python-connexion-security-function-suffix}}}(token: str) -> dict:
     """
     Validate and decode token.
     Returned value will be passed in 'token_info' parameter of your operation function, if there is one.
@@ -14,14 +14,14 @@ def info_from_{{name}}(token: str) -> dict:
     return {'scopes': ['read:pets', 'write:pets'], 'uid': 'user_id'}
 
 
-def validate_scope_{{name}}(required_scopes: List[str], token_scopes: List[str]) -> bool:
+def validate_scope_{{{vendorExtensions.x-python-connexion-security-function-suffix}}}(required_scopes: List[str], token_scopes: List[str]) -> bool:
     """ Validate required scopes are included in token scope """
     return set(required_scopes).issubset(set(token_scopes))
 
 {{/isOAuth}}
 {{#isApiKey}}
 
-def info_from_{{name}}(api_key: str, required_scopes: None) -> dict:
+def info_from_{{{vendorExtensions.x-python-connexion-security-function-suffix}}}(api_key: str, required_scopes: None) -> dict:
     """
     Check and retrieve authentication information from api_key.
     Returned value will be passed in 'token_info' parameter of your operation function, if there is one.
@@ -33,7 +33,7 @@ def info_from_{{name}}(api_key: str, required_scopes: None) -> dict:
 {{/isApiKey}}
 {{#isBasicBasic}}
 
-def info_from_{{name}}(username: str, password: str, required_scopes: None) -> dict:
+def info_from_{{{vendorExtensions.x-python-connexion-security-function-suffix}}}(username: str, password: str, required_scopes: None) -> dict:
     """
     Check and retrieve authentication information from basic auth.
     Returned value will be passed in 'token_info' parameter of your operation function, if there is one.
@@ -45,7 +45,7 @@ def info_from_{{name}}(username: str, password: str, required_scopes: None) -> d
 {{/isBasicBasic}}
 {{#isBasicBearer}}
 
-def info_from_{{name}}(token: str) -> dict:
+def info_from_{{{vendorExtensions.x-python-connexion-security-function-suffix}}}(token: str) -> dict:
     """
     Check and retrieve authentication information from custom bearer token.
     Returned value will be passed in 'token_info' parameter of your operation function, if there is one.
 
@@ -3,7 +3,7 @@ from typing import List
 {{#authMethods}}
 {{#isOAuth}}
 
-def info_from_{{name}}(token):
+def info_from_{{{vendorExtensions.x-python-connexion-security-function-suffix}}}(token):
     """
     Validate and decode token.
     Returned value will be passed in 'token_info' parameter of your operation function, if there is one.
@@ -18,7 +18,7 @@ def info_from_{{name}}(token):
     return {'scopes': ['read:pets', 'write:pets'], 'uid': 'user_id'}
 
 
-def validate_scope_{{name}}(required_scopes, token_scopes):
+def validate_scope_{{{vendorExtensions.x-python-connexion-security-function-suffix}}}(required_scopes, token_scopes):
     """
     Validate required scopes are included in token scope
 
@@ -34,7 +34,7 @@ def validate_scope_{{name}}(required_scopes, token_scopes):
 {{/isOAuth}}
 {{#isApiKey}}
 
-def info_from_{{name}}(api_key, required_scopes):
+def info_from_{{{vendorExtensions.x-python-connexion-security-function-suffix}}}(api_key, required_scopes):
     """
     Check and retrieve authentication information from api_key.
     Returned value will be passed in 'token_info' parameter of your operation function, if there is one.
@@ -52,7 +52,7 @@ def info_from_{{name}}(api_key, required_scopes):
 {{/isApiKey}}
 {{#isBasicBasic}}
 
-def info_from_{{name}}(username, password, required_scopes):
+def info_from_{{{vendorExtensions.x-python-connexion-security-function-suffix}}}(username, password, required_scopes):
     """
     Check and retrieve authentication information from basic auth.
     Returned value will be passed in 'token_info' parameter of your operation function, if there is one.
@@ -72,7 +72,7 @@ def info_from_{{name}}(username, password, required_scopes):
 {{/isBasicBasic}}
 {{#isBasicBearer}}
 
-def info_from_{{name}}(token):
+def info_from_{{{vendorExtensions.x-python-connexion-security-function-suffix}}}(token):
     """
     Check and retrieve authentication information from custom bearer token.
     Returned value will be passed in 'token_info' parameter of your operation function, if there is one.