diff --git a/app/src/main/java/com/bitchat/android/nostr/GeohashMessageHandler.kt b/app/src/main/java/com/bitchat/android/nostr/GeohashMessageHandler.kt
index ec3af4e6..b318ef69 100644
--- a/app/src/main/java/com/bitchat/android/nostr/GeohashMessageHandler.kt
+++ b/app/src/main/java/com/bitchat/android/nostr/GeohashMessageHandler.kt
@@ -59,22 +59,25 @@ class GeohashMessageHandler(
                     }
                 }
 
+                // Normalize pubkey to lowercase for consistent blocking and storage
+                val pubkey = event.pubkey.lowercase()
+
                 // Blocked users check (use injected DataManager which has loaded state)
-                if (dataManager.isGeohashUserBlocked(event.pubkey)) return@launch
+                if (dataManager.isGeohashUserBlocked(pubkey)) return@launch
 
                 // Update repository (participants, nickname, teleport)
                 // Update repository on a background-safe path; repository will post updates to LiveData
                 
                 // Update participant count (last seen) on BOTH Presence (20001) and Chat (20000) events
                 if (event.kind == NostrKind.GEOHASH_PRESENCE || event.kind == NostrKind.EPHEMERAL_EVENT) {
-                    repo.updateParticipant(subscribedGeohash, event.pubkey, Date(event.createdAt * 1000L))
+                    repo.updateParticipant(subscribedGeohash, pubkey, Date(event.createdAt * 1000L))
                 }
                 
-                event.tags.find { it.size >= 2 && it[0] == "n" }?.let { repo.cacheNickname(event.pubkey, it[1]) }
-                event.tags.find { it.size >= 2 && it[0] == "t" && it[1] == "teleport" }?.let { repo.markTeleported(event.pubkey) }
+                event.tags.find { it.size >= 2 && it[0] == "n" }?.let { repo.cacheNickname(pubkey, it[1]) }
+                event.tags.find { it.size >= 2 && it[0] == "t" && it[1] == "teleport" }?.let { repo.markTeleported(pubkey) }
                 // Register a geohash DM alias for this participant so MessageRouter can route DMs via Nostr
                 try {
-                    com.bitchat.android.nostr.GeohashAliasRegistry.put("nostr_${event.pubkey.take(16)}", event.pubkey)
+                    com.bitchat.android.nostr.GeohashAliasRegistry.put("nostr_${pubkey.take(16)}", pubkey)
                 } catch (_: Exception) { }
 
                 // Stop here for presence events - they don't produce chat messages
@@ -82,13 +85,13 @@ class GeohashMessageHandler(
 
                 // Skip our own events for message emission
                 val my = NostrIdentityBridge.deriveIdentity(subscribedGeohash, application)
-                if (my.publicKeyHex.equals(event.pubkey, true)) return@launch
+                if (my.publicKeyHex.equals(pubkey, true)) return@launch
 
                 val isTeleportPresence = event.tags.any { it.size >= 2 && it[0] == "t" && it[1] == "teleport" } &&
                                          event.content.trim().isEmpty()
                 if (isTeleportPresence) return@launch
 
-                val senderName = repo.displayNameForNostrPubkeyUI(event.pubkey)
+                val senderName = repo.displayNameForNostrPubkeyUI(pubkey)
                 val hasNonce = try { NostrProofOfWork.hasNonce(event) } catch (_: Exception) { false }
                 val msg = BitchatMessage(
                     id = event.id,
@@ -96,8 +99,8 @@ class GeohashMessageHandler(
                     content = event.content,
                     timestamp = Date(event.createdAt * 1000L),
                     isRelay = false,
-                    originalSender = repo.displayNameForNostrPubkey(event.pubkey),
-                    senderPeerID = "nostr:${event.pubkey.take(8)}",
+                    originalSender = repo.displayNameForNostrPubkey(pubkey),
+                    senderPeerID = "nostr:${pubkey.take(8)}",
                     mentions = null,
                     channel = "#$subscribedGeohash",
                     powDifficulty = try {
diff --git a/app/src/main/java/com/bitchat/android/nostr/NostrDirectMessageHandler.kt b/app/src/main/java/com/bitchat/android/nostr/NostrDirectMessageHandler.kt
index 18c12e4d..b2526810 100644
--- a/app/src/main/java/com/bitchat/android/nostr/NostrDirectMessageHandler.kt
+++ b/app/src/main/java/com/bitchat/android/nostr/NostrDirectMessageHandler.kt
@@ -62,7 +62,8 @@ class NostrDirectMessageHandler(
                     return@launch
                 }
 
-                val (content, senderPubkey, rumorTimestamp) = decryptResult
+                val (content, rawSenderPubkey, rumorTimestamp) = decryptResult
+                val senderPubkey = rawSenderPubkey.lowercase()
 
                 // If sender is blocked for geohash contexts, drop any events from this pubkey
                 // Applies to both geohash DMs (geohash != "") and account DMs (geohash == "")