diff --git a/services/web/frontend/js/features/ide-react/context/references-context.tsx b/services/web/frontend/js/features/ide-react/context/references-context.tsx
index bf886c3f56..d127806680 100644
--- a/services/web/frontend/js/features/ide-react/context/references-context.tsx
+++ b/services/web/frontend/js/features/ide-react/context/references-context.tsx
@@ -1,5 +1,5 @@
 // @ts-ignore
-import CryptoJSSHA1 from 'crypto-js/sha1'
+import { generateSHA1Hash } from '../../../shared/utils/sha1'
 import {
   createContext,
   useContext,
@@ -94,9 +94,9 @@ export const ReferencesProvider: FC = ({ children }) => {
       const docId = doc.doc_id
       const snapshot = doc._doc.snapshot
       const now = Date.now()
-      const sha1 = CryptoJSSHA1(
+      const sha1 = generateSHA1Hash(
         'blob ' + snapshot.length + '\x00' + snapshot
-      ).toString()
+      )
       const CACHE_LIFETIME = 6 * 3600 * 1000 // allow reindexing every 6 hours
       const cacheEntry = existingIndexHash[docId]
       const isCached =
diff --git a/services/web/frontend/js/ide/references/ReferencesManager.js b/services/web/frontend/js/ide/references/ReferencesManager.js
index 3ad2cde92a..6d9ffe3bdf 100644
--- a/services/web/frontend/js/ide/references/ReferencesManager.js
+++ b/services/web/frontend/js/ide/references/ReferencesManager.js
@@ -13,7 +13,7 @@ import _ from 'lodash'
  * DS207: Consider shorter variations of null checks
  * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
  */
-import CryptoJSSHA1 from 'crypto-js/sha1'
+import { generateSHA1Hash } from '../../shared/utils/sha1'
 let ReferencesManager
 
 export default ReferencesManager = class ReferencesManager {
@@ -75,9 +75,7 @@ export default ReferencesManager = class ReferencesManager {
     const docId = doc.doc_id
     const snapshot = doc._doc.snapshot
     const now = Date.now()
-    const sha1 = CryptoJSSHA1(
-      'blob ' + snapshot.length + '\x00' + snapshot
-    ).toString()
+    const sha1 = generateSHA1Hash('blob ' + snapshot.length + '\x00' + snapshot)
     const CACHE_LIFETIME = 6 * 3600 * 1000 // allow reindexing every 6 hours
     const cacheEntry = this.existingIndexHash[docId]
     const isCached =
diff --git a/services/web/frontend/js/shared/utils/crypto.js b/services/web/frontend/js/shared/utils/crypto.js
new file mode 100644
index 0000000000..b83ef2067a
--- /dev/null
+++ b/services/web/frontend/js/shared/utils/crypto.js
@@ -0,0 +1,41 @@
+/**
+ * From: https://github.com/pvorb/node-crypt/blob/master/crypt.js
+ * Copyright © 2011, Paul Vorbach. All rights reserved.
+ * Copyright © 2009, Jeff Mott. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this list of
+ *    conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
+ *    conditions and the following disclaimer in the documentation and/or other materials
+ *    provided with the distribution.
+ * 3. Neither the name Crypto-JS nor the names of its contributors may be used to endorse or
+ *    promote products derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+ * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// Convert a byte array to big-endian 32-bit words
+export function bytesToWords(bytes) {
+  const words = []
+  for (let i = 0, b = 0; i < bytes.length; i++, b += 8)
+    words[b >>> 5] |= bytes[i] << (24 - (b % 32))
+  return words
+}
+
+// Convert big-endian 32-bit words to a byte array
+export function wordsToBytes(words) {
+  const bytes = []
+  for (let b = 0; b < words.length * 32; b += 8)
+    bytes.push((words[b >>> 5] >>> (24 - (b % 32))) & 0xff)
+  return bytes
+}
diff --git a/services/web/frontend/js/shared/utils/sha1.js b/services/web/frontend/js/shared/utils/sha1.js
new file mode 100644
index 0000000000..f1167868d9
--- /dev/null
+++ b/services/web/frontend/js/shared/utils/sha1.js
@@ -0,0 +1,99 @@
+/**
+ * From https://github.com/pvorb/node-sha1/blob/master/sha1.js
+ * Copyright © 2009, Jeff Mott. All rights reserved.
+ * Copyright © 2011, Paul Vorbach. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this
+ *    list of conditions and the following disclaimer in the documentation and/or
+ *    other materials provided with the distribution.
+ * 3. Neither the name Crypto-JS nor the names of its contributors may be used to
+ *    endorse or promote products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+import { wordsToBytes, bytesToWords } from './crypto'
+
+export function generateSHA1Hash(inputString) {
+  const encoder = new TextEncoder()
+  const uint8Array = encoder.encode(inputString)
+
+  const m = bytesToWords(uint8Array)
+  const l = inputString.length * 8
+  const w = []
+  let H0 = 1732584193
+  let H1 = -271733879
+  let H2 = -1732584194
+  let H3 = 271733878
+  let H4 = -1009589776
+
+  // Padding
+  m[l >> 5] |= 0x80 << (24 - (l % 32))
+  m[(((l + 64) >>> 9) << 4) + 15] = l
+
+  for (let i = 0; i < m.length; i += 16) {
+    const a = H0
+    const b = H1
+    const c = H2
+    const d = H3
+    const e = H4
+
+    for (let j = 0; j < 80; j++) {
+      if (j < 16) w[j] = m[i + j]
+      else {
+        const n = w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16]
+        w[j] = (n << 1) | (n >>> 31)
+      }
+
+      const t =
+        ((H0 << 5) | (H0 >>> 27)) +
+        H4 +
+        (w[j] >>> 0) +
+        (j < 20
+          ? ((H1 & H2) | (~H1 & H3)) + 1518500249
+          : j < 40
+            ? (H1 ^ H2 ^ H3) + 1859775393
+            : j < 60
+              ? ((H1 & H2) | (H1 & H3) | (H2 & H3)) - 1894007588
+              : (H1 ^ H2 ^ H3) - 899497514)
+
+      H4 = H3
+      H3 = H2
+      H2 = (H1 << 30) | (H1 >>> 2)
+      H1 = H0
+      H0 = t
+    }
+
+    H0 += a
+    H1 += b
+    H2 += c
+    H3 += d
+    H4 += e
+  }
+
+  const result = wordsToBytes([H0, H1, H2, H3, H4])
+
+  // Convert array of bytes to a hex string
+  // padStart is used to ensure numbers that are
+  // less than 16 will still be converted into the two-character format
+  // For example:
+  // "5" => "05"
+  // "a" => "0a"
+  // "ff" => "ff"
+  return result.map(b => b.toString(16).padStart(2, '0')).join('')
+}
diff --git a/services/web/frontend/js/vendor/libs/sharejs.js b/services/web/frontend/js/vendor/libs/sharejs.js
index 76bcd643f2..a3140ffc3d 100644
--- a/services/web/frontend/js/vendor/libs/sharejs.js
+++ b/services/web/frontend/js/vendor/libs/sharejs.js
@@ -1,4 +1,4 @@
-import CryptoJSSHA1 from 'crypto-js/sha1'
+import { generateSHA1Hash } from '../../shared/utils/sha1'
 import { debugging, debugConsole } from '@/utils/debugging'
 
 var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();
@@ -1286,7 +1286,7 @@ export const { Doc } = (() => {
           var needToRecomputeHash = !this.__lastSubmitTimestamp || (age > RECOMPUTE_HASH_INTERVAL) || (age < 0)
           if (needToRecomputeHash || debugging) {
             // send git hash of current snapshot
-            var sha1 = CryptoJSSHA1("blob " + this.snapshot.length + "\x00" + this.snapshot).toString()
+            var sha1 = generateSHA1Hash("blob " + this.snapshot.length + "\x00" + this.snapshot)
             this.__lastSubmitTimestamp = now;
           }
         }
diff --git a/services/web/test/frontend/shared/utils/sha1.test.js b/services/web/test/frontend/shared/utils/sha1.test.js
new file mode 100644
index 0000000000..28cc5e92be
--- /dev/null
+++ b/services/web/test/frontend/shared/utils/sha1.test.js
@@ -0,0 +1,80 @@
+import { expect } from 'chai'
+
+import { generateSHA1Hash } from '../../../../frontend/js/shared/utils/sha1'
+
+function generateRandomString(length) {
+  const characters =
+    'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'
+  let result = ''
+  const charactersLength = characters.length
+  for (let i = 0; i < length; i++) {
+    result += characters.charAt(Math.floor(Math.random() * charactersLength))
+  }
+  return result
+}
+
+function generateMultipleRandomStrings(numStrings, maxLength) {
+  const randomStrings = []
+  for (let i = 0; i < numStrings; i++) {
+    const length = Math.floor(Math.random() * maxLength)
+    randomStrings.push(generateRandomString(length))
+  }
+  return [...new Set(randomStrings)]
+}
+
+describe('sha1', function () {
+  describe('generateSHA1Hash', function () {
+    const strings = generateMultipleRandomStrings(100, 1000)
+
+    it('generates 40 base16 characters', function () {
+      for (const str of strings)
+        expect(generateSHA1Hash(str)).to.match(/^[\da-f]{40}$/)
+    })
+
+    it("doesn't have collisions on a small set", function () {
+      expect(new Set(strings.map(generateSHA1Hash)).size).to.equal(
+        strings.length
+      )
+    })
+
+    it('sample string 1', function () {
+      expect(generateSHA1Hash('sample string 1')).to.equal(
+        '135028161629af5901ea2f15554730dc0de38a01'
+      )
+    })
+
+    it('sample string 2', function () {
+      expect(generateSHA1Hash('sample string 2')).to.equal(
+        'db9460374e49a7c737b609c2fb37302381f345d6'
+      )
+    })
+
+    it('abc', function () {
+      expect(generateSHA1Hash('abc')).to.equal(
+        'a9993e364706816aba3e25717850c26c9cd0d89d'
+      )
+    })
+
+    it('generates a sha1 for an empty string', function () {
+      expect(generateSHA1Hash('')).to.equal(
+        'da39a3ee5e6b4b0d3255bfef95601890afd80709'
+      )
+    })
+
+    it('abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq', function () {
+      expect(
+        generateSHA1Hash(
+          'abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq'
+        )
+      ).to.equal('84983e441c3bd26ebaae4aa1f95129e5e54670f1')
+    })
+
+    it('abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmnhijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu', function () {
+      expect(
+        generateSHA1Hash(
+          'abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmnhijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu'
+        )
+      ).to.equal('a49b2446a02c645bf419f995b67091253a04a259')
+    })
+  })
+})