diff --git a/docs/docs/develop/api-old.md b/docs/docs/develop/api-old.md
index 8cb072fc..8533f3e5 100644
--- a/docs/docs/develop/api-old.md
+++ b/docs/docs/develop/api-old.md
@@ -43,7 +43,7 @@
 | `data.comment.id`              | Number   |   -    | 评论 ID                                |
 | `data.comment.content`         | String   |   -    | 评论正文                               |
 | `data.comment.nick`            | String   |   -    | 评论者昵称                             |
-| `data.comment.email_encrypted` | String   |   -    | 评论者邮箱 MD5 加密值                  |
+| `data.comment.email_encrypted` | String   |   -    | 评论者邮箱 SHA256 加密值                |
 | `data.comment.link`            | String   |   -    | 评论者链接                             |
 | `data.comment.ua`              | String   |   -    | 评论者 User-Agent                      |
 | `data.comment.date`            | String   |   -    | 评论时间，格式为 `1970-01-01 00:00:00` |
diff --git a/internal/dao/cook.go b/internal/dao/cook.go
index 2706b403..06336d9f 100644
--- a/internal/dao/cook.go
+++ b/internal/dao/cook.go
@@ -1,6 +1,8 @@
 package dao
 
 import (
+	"strings"
+
 	"github.com/ArtalkJS/Artalk/internal/entity"
 	"github.com/ArtalkJS/Artalk/internal/utils"
 	"github.com/samber/lo"
@@ -38,7 +40,7 @@ func (dao *Dao) CookComment(c *entity.Comment) entity.CookedComment {
 		ContentMarked:  markedContent,
 		UserID:         c.UserID,
 		Nick:           user.Name,
-		EmailEncrypted: utils.GetSha256Hash(user.Email),
+		EmailEncrypted: utils.GetSha256Hash(strings.ToLower(user.Email)),
 		Link:           user.Link,
 		UA:             c.UA,
 		Date:           c.CreatedAt.Local().Format(CommonDateTimeFormat),
@@ -90,7 +92,7 @@ func (dao *Dao) CookCommentForEmail(c *entity.Comment) entity.CookedCommentForEm
 		Site:       dao.CookSite(&site),
 		CookedComment: entity.CookedComment{
 			ID:             c.ID,
-			EmailEncrypted: utils.GetSha256Hash(user.Email),
+			EmailEncrypted: utils.GetSha256Hash(strings.ToLower(user.Email)),
 			Link:           user.Link,
 			UA:             c.UA,
 			IsCollapsed:    c.IsCollapsed,
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 6d8844ac..414a1565 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -243,6 +243,9 @@ importers:
       artalk:
         specifier: workspace:^
         version: link:../artalk
+      crypto-js:
+        specifier: ^4.2.0
+        version: 4.2.0
       pinia:
         specifier: ^2.1.7
         version: 2.1.7(typescript@5.4.5)(vue@3.4.26(typescript@5.4.5))
@@ -265,6 +268,9 @@ importers:
       '@tsconfig/node18':
         specifier: ^18.2.4
         version: 18.2.4
+      '@types/crypto-js':
+        specifier: ^4.2.2
+        version: 4.2.2
       '@types/jsdom':
         specifier: ^21.1.6
         version: 21.1.6
@@ -1333,6 +1339,9 @@ packages:
   '@types/babel__traverse@7.20.5':
     resolution: {integrity: sha512-WXCyOcRtH37HAUkpXhUduaxdm82b4GSlyTqajXviN4EfiuPgNYR109xMCKvpl6zPIpua0DGlMEDCq+g8EdoheQ==}
 
+  '@types/crypto-js@4.2.2':
+    resolution: {integrity: sha512-sDOLlVbHhXpAUAL0YHDUUwDZf3iN4Bwi4W6a0W0b+QcAezUbRtH4FVb+9J4h+XFPW7l/gQ9F8qC7P+Ec4k8QVQ==}
+
   '@types/estree@1.0.5':
     resolution: {integrity: sha512-/kYRxGDLWzHOB7q+wtSUQlFrtcdUccpfy+X+9iMBpHK8QLLhx2wIPYuS5DYtR9Wa/YlZAbIovy7qVdB1Aq6Lyw==}
 
@@ -2077,6 +2086,9 @@ packages:
     resolution: {integrity: sha512-iRDPJKUPVEND7dHPO8rkbOnPpyDygcDFtWjpeWNCgy8WP2rXcxXL8TskReQl6OrB2G7+UJrags1q15Fudc7G6w==}
     engines: {node: '>= 8'}
 
+  crypto-js@4.2.0:
+    resolution: {integrity: sha512-KALDyEYgpY+Rlob/iriUtjV6d5Eq+Y191A5g4UqLAi8CyGP9N1+FdVbkc1SxKc2r4YAYqG8JzO2KGL+AizD70Q==}
+
   css-color-keywords@1.0.0:
     resolution: {integrity: sha512-FyyrDHZKEjXDpNJYvVsV960FiqQyXc/LlYmsxl2BcdMb2WPx0OGRVgTg55rPSyLSNMqP52R9r8geSp7apN3Ofg==}
     engines: {node: '>=4'}
@@ -5663,6 +5675,8 @@ snapshots:
     dependencies:
       '@babel/types': 7.24.5
 
+  '@types/crypto-js@4.2.2': {}
+
   '@types/estree@1.0.5': {}
 
   '@types/istanbul-lib-coverage@2.0.6': {}
@@ -6615,6 +6629,8 @@ snapshots:
       shebang-command: 2.0.0
       which: 2.0.2
 
+  crypto-js@4.2.0: {}
+
   css-color-keywords@1.0.0: {}
 
   css-functions-list@3.2.2: {}
diff --git a/ui/artalk-sidebar/package.json b/ui/artalk-sidebar/package.json
index f135831c..784a20ab 100644
--- a/ui/artalk-sidebar/package.json
+++ b/ui/artalk-sidebar/package.json
@@ -15,6 +15,7 @@
   },
   "dependencies": {
     "artalk": "workspace:^",
+    "crypto-js": "^4.2.0",
     "pinia": "^2.1.7",
     "vue": "^3.4.26",
     "vue-i18n": "^9.13.1",
@@ -24,6 +25,7 @@
   "devDependencies": {
     "@rushstack/eslint-patch": "^1.10.2",
     "@tsconfig/node18": "^18.2.4",
+    "@types/crypto-js": "^4.2.2",
     "@types/jsdom": "^21.1.6",
     "@vitejs/plugin-vue": "^5.0.4",
     "@vue/eslint-config-prettier": "^9.0.0",
diff --git a/ui/artalk-sidebar/src/components/Header.vue b/ui/artalk-sidebar/src/components/Header.vue
index 493fb949..4c05cfea 100644
--- a/ui/artalk-sidebar/src/components/Header.vue
+++ b/ui/artalk-sidebar/src/components/Header.vue
@@ -1,6 +1,5 @@
 <script setup lang="ts">
-// @ts-ignore
-import MD5 from '../lib/md5'
+import sha256 from 'crypto-js/sha256'
 import { storeToRefs } from 'pinia'
 import { useUserStore } from '../stores/user'
 import { useNavStore } from '../stores/nav'
@@ -15,7 +14,7 @@ const { site: curtSite, isAdmin, email } = storeToRefs(user)
 const userAvatarImgURL = computed(() => {
   const conf = artalk?.ctx.conf?.gravatar
   if (!conf) return ``
-  return `${conf.mirror.replace(/\/$/, '')}/${MD5(email.value)}?${conf.params.replace(/^\?/, '')}`
+  return `${conf.mirror.replace(/\/$/, '')}/${sha256(email.value.toLowerCase())}?${conf.params.replace(/^\?/, '')}`
 })
 
 const avatarClickHandler = () => {
diff --git a/ui/artalk-sidebar/src/lib/md5.js b/ui/artalk-sidebar/src/lib/md5.js
deleted file mode 100644
index 7d486170..00000000
--- a/ui/artalk-sidebar/src/lib/md5.js
+++ /dev/null
@@ -1,6 +0,0 @@
-/* eslint-disable */
-
-// https://stackoverflow.com/questions/14733374/how-to-generate-an-md5-file-hash-in-javascript-node-js#answer-33486055
-var MD5 = function(d){var r = M(V(Y(X(d),8*d.length)));return r.toLowerCase()};function M(d){for(var _,m="0123456789ABCDEF",f="",r=0;r<d.length;r++)_=d.charCodeAt(r),f+=m.charAt(_>>>4&15)+m.charAt(15&_);return f}function X(d){for(var _=Array(d.length>>2),m=0;m<_.length;m++)_[m]=0;for(m=0;m<8*d.length;m+=8)_[m>>5]|=(255&d.charCodeAt(m/8))<<m%32;return _}function V(d){for(var _="",m=0;m<32*d.length;m+=8)_+=String.fromCharCode(d[m>>5]>>>m%32&255);return _}function Y(d,_){d[_>>5]|=128<<_%32,d[14+(_+64>>>9<<4)]=_;for(var m=1732584193,f=-271733879,r=-1732584194,i=271733878,n=0;n<d.length;n+=16){var h=m,t=f,g=r,e=i;f=md5_ii(f=md5_ii(f=md5_ii(f=md5_ii(f=md5_hh(f=md5_hh(f=md5_hh(f=md5_hh(f=md5_gg(f=md5_gg(f=md5_gg(f=md5_gg(f=md5_ff(f=md5_ff(f=md5_ff(f=md5_ff(f,r=md5_ff(r,i=md5_ff(i,m=md5_ff(m,f,r,i,d[n+0],7,-680876936),f,r,d[n+1],12,-389564586),m,f,d[n+2],17,606105819),i,m,d[n+3],22,-1044525330),r=md5_ff(r,i=md5_ff(i,m=md5_ff(m,f,r,i,d[n+4],7,-176418897),f,r,d[n+5],12,1200080426),m,f,d[n+6],17,-1473231341),i,m,d[n+7],22,-45705983),r=md5_ff(r,i=md5_ff(i,m=md5_ff(m,f,r,i,d[n+8],7,1770035416),f,r,d[n+9],12,-1958414417),m,f,d[n+10],17,-42063),i,m,d[n+11],22,-1990404162),r=md5_ff(r,i=md5_ff(i,m=md5_ff(m,f,r,i,d[n+12],7,1804603682),f,r,d[n+13],12,-40341101),m,f,d[n+14],17,-1502002290),i,m,d[n+15],22,1236535329),r=md5_gg(r,i=md5_gg(i,m=md5_gg(m,f,r,i,d[n+1],5,-165796510),f,r,d[n+6],9,-1069501632),m,f,d[n+11],14,643717713),i,m,d[n+0],20,-373897302),r=md5_gg(r,i=md5_gg(i,m=md5_gg(m,f,r,i,d[n+5],5,-701558691),f,r,d[n+10],9,38016083),m,f,d[n+15],14,-660478335),i,m,d[n+4],20,-405537848),r=md5_gg(r,i=md5_gg(i,m=md5_gg(m,f,r,i,d[n+9],5,568446438),f,r,d[n+14],9,-1019803690),m,f,d[n+3],14,-187363961),i,m,d[n+8],20,1163531501),r=md5_gg(r,i=md5_gg(i,m=md5_gg(m,f,r,i,d[n+13],5,-1444681467),f,r,d[n+2],9,-51403784),m,f,d[n+7],14,1735328473),i,m,d[n+12],20,-1926607734),r=md5_hh(r,i=md5_hh(i,m=md5_hh(m,f,r,i,d[n+5],4,-378558),f,r,d[n+8],11,-2022574463),m,f,d[n+11],16,1839030562),i,m,d[n+14],23,-35309556),r=md5_hh(r,i=md5_hh(i,m=md5_hh(m,f,r,i,d[n+1],4,-1530992060),f,r,d[n+4],11,1272893353),m,f,d[n+7],16,-155497632),i,m,d[n+10],23,-1094730640),r=md5_hh(r,i=md5_hh(i,m=md5_hh(m,f,r,i,d[n+13],4,681279174),f,r,d[n+0],11,-358537222),m,f,d[n+3],16,-722521979),i,m,d[n+6],23,76029189),r=md5_hh(r,i=md5_hh(i,m=md5_hh(m,f,r,i,d[n+9],4,-640364487),f,r,d[n+12],11,-421815835),m,f,d[n+15],16,530742520),i,m,d[n+2],23,-995338651),r=md5_ii(r,i=md5_ii(i,m=md5_ii(m,f,r,i,d[n+0],6,-198630844),f,r,d[n+7],10,1126891415),m,f,d[n+14],15,-1416354905),i,m,d[n+5],21,-57434055),r=md5_ii(r,i=md5_ii(i,m=md5_ii(m,f,r,i,d[n+12],6,1700485571),f,r,d[n+3],10,-1894986606),m,f,d[n+10],15,-1051523),i,m,d[n+1],21,-2054922799),r=md5_ii(r,i=md5_ii(i,m=md5_ii(m,f,r,i,d[n+8],6,1873313359),f,r,d[n+15],10,-30611744),m,f,d[n+6],15,-1560198380),i,m,d[n+13],21,1309151649),r=md5_ii(r,i=md5_ii(i,m=md5_ii(m,f,r,i,d[n+4],6,-145523070),f,r,d[n+11],10,-1120210379),m,f,d[n+2],15,718787259),i,m,d[n+9],21,-343485551),m=safe_add(m,h),f=safe_add(f,t),r=safe_add(r,g),i=safe_add(i,e)}return Array(m,f,r,i)}function md5_cmn(d,_,m,f,r,i){return safe_add(bit_rol(safe_add(safe_add(_,d),safe_add(f,i)),r),m)}function md5_ff(d,_,m,f,r,i,n){return md5_cmn(_&m|~_&f,d,_,r,i,n)}function md5_gg(d,_,m,f,r,i,n){return md5_cmn(_&f|m&~f,d,_,r,i,n)}function md5_hh(d,_,m,f,r,i,n){return md5_cmn(_^m^f,d,_,r,i,n)}function md5_ii(d,_,m,f,r,i,n){return md5_cmn(m^(_|~f),d,_,r,i,n)}function safe_add(d,_){var m=(65535&d)+(65535&_);return(d>>16)+(_>>16)+(m>>16)<<16|65535&m}function bit_rol(d,_){return d<<_|d>>>32-_}
-
-export default MD5
diff --git a/ui/artalk/src/comment/comment-node.ts b/ui/artalk/src/comment/comment-node.ts
index 868b45aa..eeada010 100644
--- a/ui/artalk/src/comment/comment-node.ts
+++ b/ui/artalk/src/comment/comment-node.ts
@@ -204,7 +204,7 @@ export default class CommentNode {
     return Utils.getGravatarURL({
       mirror: this.opts.gravatar.mirror,
       params: this.opts.gravatar.params,
-      emailMD5: this.data.email_encrypted,
+      emailHash: this.data.email_encrypted,
     })
   }
 
diff --git a/ui/artalk/src/lib/utils.ts b/ui/artalk/src/lib/utils.ts
index a011df19..e9510675 100644
--- a/ui/artalk/src/lib/utils.ts
+++ b/ui/artalk/src/lib/utils.ts
@@ -107,8 +107,8 @@ export function timeAgo(date: Date, $t: Function = (n: string) => n) {
   }
 }
 
-export function getGravatarURL(opts: { params: string; mirror: string; emailMD5: string }) {
-  return `${opts.mirror.replace(/\/$/, '')}/${opts.emailMD5}?${opts.params.replace(/^\?/, '')}`
+export function getGravatarURL(opts: { params: string; mirror: string; emailHash: string }) {
+  return `${opts.mirror.replace(/\/$/, '')}/${opts.emailHash}?${opts.params.replace(/^\?/, '')}`
 }
 
 export function sleep(ms: number) {