diff --git a/charts/trek/Chart.yaml b/charts/trek/Chart.yaml
index 6f18fc134..1ffd0a32d 100644
--- a/charts/trek/Chart.yaml
+++ b/charts/trek/Chart.yaml
@@ -1,5 +1,5 @@
 apiVersion: v2
 name: trek
-version: 5.1.0
+version: 5.1.1
 description: Minimal Helm chart for TREK app
-appVersion: "5.1.0"
+appVersion: "5.1.1"
diff --git a/client/package.json b/client/package.json
index 89ec48880..f9e842e1f 100644
--- a/client/package.json
+++ b/client/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@trek/client",
-  "version": "5.1.0",
+  "version": "5.1.1",
   "engines": {
     "node": "^22.22.2 || ^24.15.0 || >=26.0.0"
   },
diff --git a/package-lock.json b/package-lock.json
index 846516dc6..a01ec6c3b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@trek/root",
-  "version": "5.1.0",
+  "version": "5.1.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@trek/root",
-      "version": "5.1.0",
+      "version": "5.1.1",
       "workspaces": [
         "client",
         "server",
@@ -29,7 +29,7 @@
     },
     "client": {
       "name": "@trek/client",
-      "version": "5.1.0",
+      "version": "5.1.1",
       "dependencies": {
         "@assistant-ui/react": "0.15.25",
         "@capacitor/android": "^8.5.0",
@@ -4135,9 +4135,6 @@
         "arm"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "LGPL-3.0-or-later",
       "optional": true,
       "os": [
@@ -4155,9 +4152,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "LGPL-3.0-or-later",
       "optional": true,
       "os": [
@@ -4175,9 +4169,6 @@
         "ppc64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "LGPL-3.0-or-later",
       "optional": true,
       "os": [
@@ -4195,9 +4186,6 @@
         "riscv64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "LGPL-3.0-or-later",
       "optional": true,
       "os": [
@@ -4215,9 +4203,6 @@
         "s390x"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "LGPL-3.0-or-later",
       "optional": true,
       "os": [
@@ -4235,9 +4220,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "LGPL-3.0-or-later",
       "optional": true,
       "os": [
@@ -4254,9 +4236,6 @@
       "cpu": [
         "arm64"
       ],
-      "libc": [
-        "musl"
-      ],
       "license": "LGPL-3.0-or-later",
       "optional": true,
       "os": [
@@ -4273,9 +4252,6 @@
       "cpu": [
         "x64"
       ],
-      "libc": [
-        "musl"
-      ],
       "license": "LGPL-3.0-or-later",
       "optional": true,
       "os": [
@@ -4293,9 +4269,6 @@
         "arm"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "Apache-2.0",
       "optional": true,
       "os": [
@@ -4319,9 +4292,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "Apache-2.0",
       "optional": true,
       "os": [
@@ -4345,9 +4315,6 @@
         "ppc64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "Apache-2.0",
       "optional": true,
       "os": [
@@ -4371,9 +4338,6 @@
         "riscv64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "Apache-2.0",
       "optional": true,
       "os": [
@@ -4397,9 +4361,6 @@
         "s390x"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "Apache-2.0",
       "optional": true,
       "os": [
@@ -4423,9 +4384,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "Apache-2.0",
       "optional": true,
       "os": [
@@ -4448,9 +4406,6 @@
       "cpu": [
         "arm64"
       ],
-      "libc": [
-        "musl"
-      ],
       "license": "Apache-2.0",
       "optional": true,
       "os": [
@@ -4473,9 +4428,6 @@
       "cpu": [
         "x64"
       ],
-      "libc": [
-        "musl"
-      ],
       "license": "Apache-2.0",
       "optional": true,
       "os": [
@@ -9897,7 +9849,8 @@
       "optional": true,
       "os": [
         "android"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-android-arm64": {
       "version": "4.62.0",
@@ -9911,7 +9864,8 @@
       "optional": true,
       "os": [
         "android"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-darwin-arm64": {
       "version": "4.62.0",
@@ -9925,7 +9879,8 @@
       "optional": true,
       "os": [
         "darwin"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-darwin-x64": {
       "version": "4.62.0",
@@ -9939,7 +9894,8 @@
       "optional": true,
       "os": [
         "darwin"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-freebsd-arm64": {
       "version": "4.62.0",
@@ -9953,7 +9909,8 @@
       "optional": true,
       "os": [
         "freebsd"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-freebsd-x64": {
       "version": "4.62.0",
@@ -9967,7 +9924,8 @@
       "optional": true,
       "os": [
         "freebsd"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-linux-arm-gnueabihf": {
       "version": "4.62.0",
@@ -9981,7 +9939,8 @@
       "optional": true,
       "os": [
         "linux"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-linux-arm-musleabihf": {
       "version": "4.62.0",
@@ -9995,7 +9954,8 @@
       "optional": true,
       "os": [
         "linux"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-linux-arm64-gnu": {
       "version": "4.62.0",
@@ -10009,7 +9969,8 @@
       "optional": true,
       "os": [
         "linux"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-linux-arm64-musl": {
       "version": "4.62.0",
@@ -10036,7 +9997,8 @@
       "optional": true,
       "os": [
         "linux"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-linux-loong64-musl": {
       "version": "4.62.0",
@@ -10050,7 +10012,8 @@
       "optional": true,
       "os": [
         "linux"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-linux-ppc64-gnu": {
       "version": "4.62.0",
@@ -10064,7 +10027,8 @@
       "optional": true,
       "os": [
         "linux"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-linux-ppc64-musl": {
       "version": "4.62.0",
@@ -10078,7 +10042,8 @@
       "optional": true,
       "os": [
         "linux"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-linux-riscv64-gnu": {
       "version": "4.62.0",
@@ -10092,7 +10057,8 @@
       "optional": true,
       "os": [
         "linux"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-linux-riscv64-musl": {
       "version": "4.62.0",
@@ -10106,7 +10072,8 @@
       "optional": true,
       "os": [
         "linux"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-linux-s390x-gnu": {
       "version": "4.62.0",
@@ -10120,7 +10087,8 @@
       "optional": true,
       "os": [
         "linux"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-linux-x64-gnu": {
       "version": "4.62.0",
@@ -10134,7 +10102,8 @@
       "optional": true,
       "os": [
         "linux"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-linux-x64-musl": {
       "version": "4.62.0",
@@ -10161,7 +10130,8 @@
       "optional": true,
       "os": [
         "openbsd"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-openharmony-arm64": {
       "version": "4.62.0",
@@ -10175,7 +10145,8 @@
       "optional": true,
       "os": [
         "openharmony"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-win32-arm64-msvc": {
       "version": "4.62.0",
@@ -10189,7 +10160,8 @@
       "optional": true,
       "os": [
         "win32"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-win32-ia32-msvc": {
       "version": "4.62.0",
@@ -10203,7 +10175,8 @@
       "optional": true,
       "os": [
         "win32"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-win32-x64-gnu": {
       "version": "4.62.0",
@@ -10217,7 +10190,8 @@
       "optional": true,
       "os": [
         "win32"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@rollup/rollup-win32-x64-msvc": {
       "version": "4.62.0",
@@ -10231,7 +10205,8 @@
       "optional": true,
       "os": [
         "win32"
-      ]
+      ],
+      "peer": true
     },
     "node_modules/@scarf/scarf": {
       "version": "1.4.0",
@@ -24841,9 +24816,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -24861,9 +24833,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -24881,9 +24850,6 @@
         "ppc64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -24901,9 +24867,6 @@
         "s390x"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -24921,9 +24884,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -24941,9 +24901,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -26036,7 +25993,7 @@
     },
     "server": {
       "name": "@trek/server",
-      "version": "5.1.0",
+      "version": "5.1.1",
       "dependencies": {
         "@aws-lite/client": "^0.23.7",
         "@aws-lite/s3": "^0.2.7",
@@ -26415,7 +26372,7 @@
     },
     "shared": {
       "name": "@trek/shared",
-      "version": "5.1.0",
+      "version": "5.1.1",
       "dependencies": {
         "isomorphic-dompurify": "^3.23.0",
         "zod": "^4.6.7"
diff --git a/package.json b/package.json
index cd920051b..2e525f533 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@trek/root",
   "private": true,
-  "version": "5.1.0",
+  "version": "5.1.1",
   "engines": {
     "node": "^22.22.2 || ^24.15.0 || >=26.0.0"
   },
diff --git a/server/package.json b/server/package.json
index 11f70dad8..9878f9b3d 100644
--- a/server/package.json
+++ b/server/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@trek/server",
-  "version": "5.1.0",
+  "version": "5.1.1",
   "engines": {
     "node": "^22.22.2 || ^24.15.0 || >=26.0.0"
   },
diff --git a/server/src/nest/service-identity/registration-dialect.ts b/server/src/nest/service-identity/registration-dialect.ts
index 6e12c7c67..11e562c2c 100644
--- a/server/src/nest/service-identity/registration-dialect.ts
+++ b/server/src/nest/service-identity/registration-dialect.ts
@@ -1,5 +1,5 @@
 /**
- * How TREK 5.1.0 registers with the TREK services.
+ * How TREK 5.1.1 registers with the TREK services.
  *
  * The issuer writes this file for each release and the release pipeline
  * commits it with the version bump. It is not edited by hand, and its layout
@@ -8,20 +8,49 @@
  */
 import type { DialectSelfCheck, RegistrationDialect } from './registration-dialect.types';
 
-import { createHash, createHmac, pbkdf2Sync } from 'node:crypto';
-import { crc32 } from 'node:zlib';
+import { createHash, pbkdf2Sync } from 'node:crypto';
 
-const DIALECT = '_53EjggnrEZi';
-const PLATEAU_JUNIPER = Buffer.from('e0a200e6a45b6507328ae0f3a781e488ad16c4a56335d2243e6b61989149c23b', 'hex');
-const RIVER_CANAL = 'abcdefghijklmnopqrstuvwxyz234567';
+const DIALECT = 'uPqlvaOK1lTg';
+const REEF_FERN = Buffer.from('f8ae4b4d3888cd3120ee6bd281eba75f55647ea1a4523fcebfc586f9cb5391e9', 'hex');
 
-function pier(input: Buffer, order: number[]): Buffer {
+function citadel(input: Buffer, width: number): Buffer {
   const out = Buffer.from(input);
-  order.forEach((from, to) => out.writeUInt8(input.readUInt8(from), to));
+  for (let i = 0; i + width <= out.length; i += width) out.subarray(i, i + width).reverse();
   return out;
 }
 
-function kettle(value: number): Buffer {
+function lichen(input: Buffer, start: number): Buffer {
+  const out = Buffer.from(input);
+  for (let offset = 0; offset < out.length; offset += 32) {
+    const counter = Buffer.alloc(2);
+    counter.writeUInt16LE((start + offset / 32) & 0xffff);
+    const block = createHash('sha256').update(REEF_FERN).update(counter).digest();
+    for (let j = offset; j < Math.min(offset + 32, out.length); j++) {
+      out.writeUInt8(out.readUInt8(j) ^ block.readUInt8(j - offset), j);
+    }
+  }
+  return out;
+}
+
+function dale(part: Buffer): Buffer {
+  const head = Buffer.alloc(2);
+  head.writeUInt16BE(part.length);
+  return Buffer.concat([head, part]);
+}
+
+function sleet(value: number): Buffer {
+  const out = Buffer.alloc(8);
+  out.writeBigUInt64LE(BigInt(value));
+  return out;
+}
+
+function grove(a: Buffer, b: Buffer): Buffer {
+  const parts: Buffer[] = [];
+  for (let i = 0; i < Math.max(a.length, b.length); i++) parts.push(a.subarray(i, i + 1), b.subarray(i, i + 1));
+  return Buffer.concat(parts);
+}
+
+function boulder(value: number): Buffer {
   const out: number[] = [];
   let rest = value;
   do {
@@ -32,92 +61,48 @@ function kettle(value: number): Buffer {
   return Buffer.from(out);
 }
 
-function sorrel(input: Buffer): string {
-  const bits = [...input].map((byte) => byte.toString(2).padStart(8, '0')).join('');
-  let out = '';
-  for (let i = 0; i < bits.length; i += 5) {
-    out += RIVER_CANAL.charAt(parseInt(bits.slice(i, i + 5).padEnd(5, '0'), 2));
-  }
-  return out;
-}
-
-function barrel(value: number): Buffer {
-  const out = Buffer.alloc(4);
-  out.writeUInt32BE(value >>> 0);
-  return out;
-}
-
-function slate7(alg: string, size: number, data: Buffer): Buffer {
-  return createHash(alg, { outputLength: size }).update(data).digest();
-}
-
-function lava(input: Buffer, size: number): Buffer {
-  const out = Buffer.alloc(size);
-  input.forEach((byte, i) => out.writeUInt8(out.readUInt8(i % size) ^ byte, i % size));
-  return out;
-}
-
-function candle(input: Buffer, rotation: number, consts: Buffer): Buffer {
-  const out = Buffer.from(input);
-  let previous = 0;
-  for (let i = 0; i + 4 <= out.length; i += 4) {
-    const word = (out.readUInt32LE(i) + consts.readUInt32BE(i % consts.length)) >>> 0;
-    previous = (((word << rotation) | (word >>> (32 - rotation))) ^ previous) >>> 0;
-    out.writeUInt32LE(previous, i);
-  }
-  return out;
-}
-
 export const registrationDialect: RegistrationDialect = {
   id: DIALECT,
-  releasedFor: '5.1.0',
-  createdAt: '2026-10-31',
+  releasedFor: '5.1.1',
+  createdAt: '2026-11-08',
   challengePath: `/v1/register/${DIALECT}/challenge`,
   registerPath: `/v1/register/${DIALECT}`,
-  begin({ challenge, version, random, nowSeconds }) {
-    const zephyr = Buffer.from(challenge.c, 'utf8');
-    const hollow = Buffer.from(version, 'utf8');
-    const tide = createHash('sha256').update(zephyr).digest();
-    const fossil = Buffer.from([0x63]);
-    const delta = Buffer.concat([hollow, fossil, PLATEAU_JUNIPER, fossil, tide]);
-    const cherry = createHmac('sha256', delta).update(hollow).digest();
-    const barge = Buffer.from(cherry.subarray(6, 26));
-    const gull = Buffer.from('b689ff5d4dbea8f47007ef8acb40fe08d6737d2627f5f206', 'hex');
-    const wren = candle(candle(barge, 2, gull), 15, gull);
+  begin({ challenge, version, random }) {
+    const olive = Buffer.from(challenge.c, 'utf8');
+    const cactus = Buffer.from(version, 'utf8');
+    const cypress = createHash('sha256').update(olive).digest();
+    const creek = Buffer.concat([olive, cactus].map(dale));
+    const cairn = createHash('shake256', { outputLength: 0x15 }).update(creek).digest();
     return {
       work(nonce) {
-        const canyon = Buffer.concat([random, zephyr, hollow, Buffer.from(`${nonce}`)]);
-        const pollen = Buffer.from(canyon.map((byte) => (byte * 0x73 + 62) & 0xff));
-        const otter = Buffer.from([
-          4, 12, 1, 5, 0xe, 8, 7, 0xd, 9, 3, 0xb, 0xa, 0, 2, 6,
-        ].map((from) => pollen.readUInt8(from)));
-        const river5 = Buffer.concat([otter, pollen.subarray(15)]);
-        const prairie = lava(river5, 20);
-        const boulder = createHmac('sha384', PLATEAU_JUNIPER).update(prairie).digest();
-        const jetty = pier(boulder, [
-          0x16, 0, 0xd, 0xb, 18, 20, 0x15, 23, 10, 19, 8, 0x11, 4, 0xe, 2, 7, 24, 9, 0xf, 6, 3, 1, 25, 0x10, 0xc, 5,
+        const breeze = Buffer.from([0xe1]);
+        const summit = Buffer.concat([
+          cactus, breeze, random, breeze, olive, breeze, boulder(nonce), breeze, REEF_FERN,
         ]);
-        return { password: jetty, salt: wren };
+        const stamp = Buffer.from([
+          ...summit.subarray(0xb % summit.length), ...summit.subarray(0, 0xb % summit.length),
+        ]);
+        const ember = createHash('blake2b512').update(stamp).digest();
+        const dove = lichen(ember, 254);
+        const autumn = createHash('blake2b512').update(dove).digest();
+        return { password: autumn, salt: cairn };
       },
       request(nonce) {
-        const slate = Buffer.concat([
-          barrel(nowSeconds), Buffer.from([104]), zephyr, Buffer.from([104]), random, Buffer.from([104]), tide,
-          Buffer.from([104]), PLATEAU_JUNIPER.subarray(15, 0x1b), Buffer.from([104]), kettle(nonce), Buffer.from([104]),
-          hollow,
-        ]);
-        const dawn = pbkdf2Sync(slate, random, 0x1b, 0x1d, 'sha256');
-        const crane = Buffer.concat([dawn, barrel(crc32(dawn))]);
-        const shore = slate7('shake256', 51, crane);
+        const barley = Buffer.concat([sleet(nonce), olive, cactus]);
+        const wren = grove(barley, cypress);
+        const chapel = citadel(wren, 4);
+        const lava = pbkdf2Sync(chapel, olive, 19, 29, 'sha256');
         return {
           body: {
-            'glade-wisteria': String(nonce),
-            'stamp-drift': challenge.c,
-            jade: random.toString('hex'),
-            harrier: nowSeconds,
-            'apple-marble': version,
-            'dew-basin': 'timber-803',
+            pilgrim: {
+              harvest: version,
+              lindenQuartz: challenge.c,
+              plateauSorrel: nonce,
+              apple: 'nest-421',
+              harvestHollow: random.toString('hex'),
+            },
           },
-          headers: { 'X-TREK-Spruce-Otter': sorrel(shore) },
+          headers: { 'X-TREK-Quill-Bramble': lava.toString('hex') },
         };
       },
     };
@@ -126,13 +111,13 @@ export const registrationDialect: RegistrationDialect = {
 
 /** Fixed inputs and what this module must make of them; TREK's tests and release job run it. */
 export const SELF_CHECK: DialectSelfCheck = {
-  challenge: { c: 'v1.selfcheck._53EjggnrEZi', alg: 'scrypt', N: 16, r: 1, p: 1, bits: 0, expires_at: 1 },
-  version: '5.1.0',
+  challenge: { c: 'v1.selfcheck.uPqlvaOK1lTg', alg: 'scrypt', N: 16, r: 1, p: 1, bits: 0, expires_at: 1 },
+  version: '5.1.1',
   random: '000102030405060708090a0b0c0d0e0f',
   nowSeconds: 1800000000,
   nonce: 41,
-  inputSha256: '3492823dc72bc3566dd8a483fbb041db15235d8069387e6ecd5df4b67d776a63',
-  saltSha256: '91104fa382a167ba804e06ac859aff52fe9107b420c0880a1ccd319f6699bfe2',
-  scrypt: '0bf159d19acf7d51c23759e1d71b5ddb9d8b974811ca3478193eca280e0a0101',
-  requestSha256: '21b99ccdccc6c9ad77109170d26cd9ab3b41d2243d3e9012fdb3dbc3e69d8d9c',
+  inputSha256: '51bf94954bef8fb0bd92426ffbd3a4301cc26aacc2f1392e36a3589c3d368eed',
+  saltSha256: 'f574427b733f5f3307704d8e967654cd8a2a1b7cf1ea37c79d682aed6253ab2d',
+  scrypt: '9603a88e384e7b6a99e79883351d9786ab5294bfe83bb9b80979ddba279d8515',
+  requestSha256: '30fb4cbca72c689c6b66ba741bd6432a112f0f424619b15ef621935c3dfddf6d',
 };
diff --git a/shared/package.json b/shared/package.json
index c9fc58ea3..d114e5b72 100644
--- a/shared/package.json
+++ b/shared/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@trek/shared",
-  "version": "5.1.0",
+  "version": "5.1.1",
   "engines": {
     "node": "^22.22.2 || ^24.15.0 || >=26.0.0"
   },