diff --git a/EnvelopeGenerator.API/Controllers/CacheController.cs b/EnvelopeGenerator.API/Controllers/CacheController.cs
index e1da376a..8b15dc46 100644
--- a/EnvelopeGenerator.API/Controllers/CacheController.cs
+++ b/EnvelopeGenerator.API/Controllers/CacheController.cs
@@ -5,6 +5,7 @@ using Microsoft.Extensions.Options;
 using System.Text.Json;
 using EnvelopeGenerator.API.Options;
 using EnvelopeGenerator.Domain.Constants;
+using EnvelopeGenerator.API.Extensions;
 
 namespace EnvelopeGenerator.API.Controllers;
 
@@ -18,18 +19,19 @@ public class CacheController(
     IDistributedCache cache,
     IOptions<CacheOptions> cacheOptions) : ControllerBase
 {
-    private const string SignatureCacheKeyPrefix = "signature:91751687-8ae6-4777-bf5f-b8846085e62e:";
+    private const string SignatureCacheKeyPrefix = "envelope-generator.receiver-ui.signature:";
 
     /// <summary>
     /// Stores a receiver's signature in cache for the specified envelope.
     /// </summary>
+    [Authorize(Policy = AuthPolicy.Receiver)]
     [HttpPost("SignatureCapture/{envelopeKey}")]
     public async Task<IActionResult> SaveSignature(
-        string envelopeKey,
+        [FromRoute] string envelopeKey,
         [FromBody] SignatureCacheRequest request,
         CancellationToken cancel)
     {
-        var cacheKey = $"{SignatureCacheKeyPrefix}{envelopeKey}";
+        var cacheKey = $"{SignatureCacheKeyPrefix}{User.ReceiverSignature}";
         var json = JsonSerializer.Serialize(request);
         
         var options = cacheOptions.Value.SignatureCacheExpiration.HasValue
@@ -44,10 +46,11 @@ public class CacheController(
     /// <summary>
     /// Retrieves a cached signature for the specified envelope.
     /// </summary>
+    [Authorize(Policy = AuthPolicy.Receiver)]
     [HttpGet("SignatureCapture/{envelopeKey}")]
-    public async Task<IActionResult> GetSignature(string envelopeKey, CancellationToken cancel)
+    public async Task<IActionResult> GetSignature([FromRoute] string envelopeKey, CancellationToken cancel)
     {
-        var cacheKey = $"{SignatureCacheKeyPrefix}{envelopeKey}";
+        var cacheKey = $"{SignatureCacheKeyPrefix}{User.ReceiverSignature}";
         var json = await cache.GetStringAsync(cacheKey, cancel);
 
         if (json is null)
@@ -60,10 +63,11 @@ public class CacheController(
     /// <summary>
     /// Deletes a cached signature for the specified envelope.
     /// </summary>
+    [Authorize(Policy = AuthPolicy.Receiver)]
     [HttpDelete("SignatureCapture/{envelopeKey}")]
-    public async Task<IActionResult> DeleteSignature(string envelopeKey, CancellationToken cancel)
+    public async Task<IActionResult> DeleteSignature([FromRoute] string envelopeKey, CancellationToken cancel)
     {
-        var cacheKey = $"{SignatureCacheKeyPrefix}{envelopeKey}";
+        var cacheKey = $"{SignatureCacheKeyPrefix}{User.ReceiverSignature}";
         await cache.RemoveAsync(cacheKey, cancel);
 
         return Ok();
@@ -74,9 +78,7 @@ public class CacheController(
 /// Request model for caching signature data.
 /// </summary>
 public sealed record SignatureCacheRequest(
-    string? DataUrl,
-    string? FullName,
-    string? Position,
-    string? Place);
-
-
+    string DataUrl,
+    string FullName,
+    string Place,
+    string? Position = null);
\ No newline at end of file