diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index 0bc9cdb8a..57b93be51 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -169,7 +169,6 @@ dependencies {
 
     implementation(libs.bundles.filemojicompat)
 
-    implementation(libs.bouncycastle)
     implementation(libs.unified.push)
 
     implementation(libs.bundles.xmldiff)
diff --git a/app/lint-baseline.xml b/app/lint-baseline.xml
index 4c604aefa..57f0081e0 100644
--- a/app/lint-baseline.xml
+++ b/app/lint-baseline.xml
@@ -1,19 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<issues format="6" by="lint 8.7.2" type="baseline" client="gradle" dependencies="false" name="AGP (8.7.2)" variant="all" version="8.7.2">
-
-    <issue
-        id="InvalidPackage"
-        message="Invalid package reference in org.bouncycastle:bcprov-jdk15on; not included in Android: `javax.naming.directory`. Referenced from `org.bouncycastle.jce.provider.CrlCache`.">
-        <location
-            file="$GRADLE_USER_HOME/caches/modules-2/files-2.1/org.bouncycastle/bcprov-jdk15on/1.70/4636a0d01f74acaf28082fb62b317f1080118371/bcprov-jdk15on-1.70.jar"/>
-    </issue>
-
-    <issue
-        id="InvalidPackage"
-        message="Invalid package reference in org.bouncycastle:bcprov-jdk15on; not included in Android: `javax.naming`. Referenced from `org.bouncycastle.jce.provider.X509LDAPCertStoreSpi`.">
-        <location
-            file="$GRADLE_USER_HOME/caches/modules-2/files-2.1/org.bouncycastle/bcprov-jdk15on/1.70/4636a0d01f74acaf28082fb62b317f1080118371/bcprov-jdk15on-1.70.jar"/>
-    </issue>
+<issues format="6" by="lint 8.5.2" type="baseline" client="gradle" dependencies="false" name="AGP (8.5.2)" variant="all" version="8.5.2">
 
     <issue
         id="InvalidPackage"
@@ -173,7 +159,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-sl/strings.xml"
-            line="174"
+            line="173"
             column="5"/>
     </issue>
 
@@ -184,7 +170,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-cs/strings.xml"
-            line="183"
+            line="182"
             column="5"/>
     </issue>
 
@@ -195,7 +181,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-bn-rIN/strings.xml"
-            line="190"
+            line="189"
             column="5"/>
     </issue>
 
@@ -217,7 +203,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-sl/strings.xml"
-            line="208"
+            line="207"
             column="5"/>
     </issue>
 
@@ -228,7 +214,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-ca/strings.xml"
-            line="225"
+            line="224"
             column="5"/>
     </issue>
 
@@ -239,7 +225,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-cs/strings.xml"
-            line="226"
+            line="225"
             column="5"/>
     </issue>
 
@@ -250,7 +236,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-bn-rIN/strings.xml"
-            line="231"
+            line="230"
             column="5"/>
     </issue>
 
@@ -261,7 +247,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-hi/strings.xml"
-            line="259"
+            line="258"
             column="5"/>
     </issue>
 
@@ -272,7 +258,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-ca/strings.xml"
-            line="262"
+            line="261"
             column="5"/>
     </issue>
 
@@ -283,7 +269,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-ca/strings.xml"
-            line="266"
+            line="265"
             column="5"/>
     </issue>
 
@@ -294,7 +280,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-cs/strings.xml"
-            line="267"
+            line="266"
             column="5"/>
     </issue>
 
@@ -305,7 +291,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-cs/strings.xml"
-            line="272"
+            line="271"
             column="5"/>
     </issue>
 
@@ -316,7 +302,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-ca/strings.xml"
-            line="291"
+            line="290"
             column="5"/>
     </issue>
 
@@ -327,7 +313,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-cs/strings.xml"
-            line="302"
+            line="301"
             column="5"/>
     </issue>
 
@@ -338,7 +324,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-cs/strings.xml"
-            line="316"
+            line="315"
             column="5"/>
     </issue>
 
@@ -349,7 +335,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-cs/strings.xml"
-            line="321"
+            line="320"
             column="5"/>
     </issue>
 
@@ -360,7 +346,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-cs/strings.xml"
-            line="326"
+            line="325"
             column="5"/>
     </issue>
 
@@ -371,7 +357,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-bg/strings.xml"
-            line="358"
+            line="357"
             column="5"/>
     </issue>
 
@@ -382,7 +368,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-ca/strings.xml"
-            line="358"
+            line="357"
             column="5"/>
     </issue>
 
@@ -393,7 +379,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-ca/strings.xml"
-            line="384"
+            line="383"
             column="5"/>
     </issue>
 
@@ -404,7 +390,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-ca/strings.xml"
-            line="388"
+            line="387"
             column="5"/>
     </issue>
 
@@ -415,7 +401,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-ca/strings.xml"
-            line="392"
+            line="391"
             column="5"/>
     </issue>
 
@@ -426,7 +412,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-ca/strings.xml"
-            line="396"
+            line="395"
             column="5"/>
     </issue>
 
@@ -437,7 +423,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-cs/strings.xml"
-            line="404"
+            line="403"
             column="5"/>
     </issue>
 
@@ -448,7 +434,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-cs/strings.xml"
-            line="409"
+            line="408"
             column="5"/>
     </issue>
 
@@ -459,7 +445,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-ca/strings.xml"
-            line="412"
+            line="411"
             column="5"/>
     </issue>
 
@@ -470,7 +456,7 @@
         errorLine2="    ^">
         <location
             file="src/main/res/values-cs/strings.xml"
-            line="414"
+            line="413"
             column="5"/>
     </issue>
 
@@ -569,7 +555,7 @@
         errorLine2="                                            ^">
         <location
             file="src/main/res/values-nb-rNO/strings.xml"
-            line="96"
+            line="95"
             column="45"/>
     </issue>
 
@@ -580,7 +566,7 @@
         errorLine2="                                           ^">
         <location
             file="src/main/res/values-nb-rNO/strings.xml"
-            line="100"
+            line="99"
             column="44"/>
     </issue>
 
@@ -591,7 +577,7 @@
         errorLine2="                                                ^">
         <location
             file="src/main/res/values-nb-rNO/strings.xml"
-            line="101"
+            line="100"
             column="49"/>
     </issue>
 
@@ -602,7 +588,7 @@
         errorLine2="                                     ^">
         <location
             file="src/main/res/values-nb-rNO/strings.xml"
-            line="104"
+            line="103"
             column="38"/>
     </issue>
 
@@ -613,7 +599,7 @@
         errorLine2="                                                                     ^">
         <location
             file="src/main/res/values-nb-rNO/strings.xml"
-            line="119"
+            line="118"
             column="70"/>
     </issue>
 
@@ -624,7 +610,7 @@
         errorLine2="                                                                             ^">
         <location
             file="src/main/res/values-nb-rNO/strings.xml"
-            line="152"
+            line="151"
             column="78"/>
     </issue>
 
@@ -635,7 +621,7 @@
         errorLine2="                                                                ^">
         <location
             file="src/main/res/values-nb-rNO/strings.xml"
-            line="158"
+            line="157"
             column="65"/>
     </issue>
 
@@ -646,7 +632,7 @@
         errorLine2="                               ^">
         <location
             file="src/main/res/values-nb-rNO/strings.xml"
-            line="194"
+            line="193"
             column="32"/>
     </issue>
 
@@ -657,7 +643,7 @@
         errorLine2="                                          ^">
         <location
             file="src/main/res/values-nb-rNO/strings.xml"
-            line="262"
+            line="261"
             column="43"/>
     </issue>
 
@@ -668,7 +654,7 @@
         errorLine2="                                                                                     ^">
         <location
             file="src/main/res/values-nb-rNO/strings.xml"
-            line="385"
+            line="384"
             column="86"/>
     </issue>
 
@@ -679,7 +665,7 @@
         errorLine2="                                                  ^">
         <location
             file="src/main/res/values-nb-rNO/strings.xml"
-            line="501"
+            line="500"
             column="51"/>
     </issue>
 
@@ -690,7 +676,7 @@
         errorLine2="                                          ^">
         <location
             file="src/main/res/values-nb-rNO/strings.xml"
-            line="622"
+            line="619"
             column="43"/>
     </issue>
 
@@ -701,7 +687,7 @@
         errorLine2="                                                  ^">
         <location
             file="src/main/res/values-nb-rNO/strings.xml"
-            line="714"
+            line="711"
             column="51"/>
     </issue>
 
@@ -712,7 +698,7 @@
         errorLine2="                                                                   ^">
         <location
             file="src/main/res/values-nb-rNO/strings.xml"
-            line="738"
+            line="735"
             column="68"/>
     </issue>
 
@@ -745,7 +731,7 @@
         errorLine2="    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~">
         <location
             file="src/main/res/values/strings.xml"
-            line="104"
+            line="105"
             column="5"/>
     </issue>
 
@@ -910,7 +896,7 @@
         errorLine2="        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~">
         <location
             file="src/main/java/app/pachli/components/account/AccountActivity.kt"
-            line="515"
+            line="518"
             column="9"/>
     </issue>
 
@@ -1119,7 +1105,7 @@
         errorLine2="                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~">
         <location
             file="src/main/res/values/donottranslate.xml"
-            line="263"
+            line="265"
             column="19"/>
     </issue>
 
@@ -1130,7 +1116,7 @@
         errorLine2="                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~">
         <location
             file="src/main/res/values/donottranslate.xml"
-            line="268"
+            line="270"
             column="19"/>
     </issue>
 
@@ -1262,7 +1248,7 @@
         errorLine2="            ~~~~~~~~~~~~~~~~~~~~~~~~~~">
         <location
             file="src/main/res/values/strings.xml"
-            line="106"
+            line="107"
             column="13"/>
     </issue>
 
@@ -1273,7 +1259,7 @@
         errorLine2="            ~~~~~~~~~~~~~~~~~~~~~~~~">
         <location
             file="src/main/res/values/strings.xml"
-            line="114"
+            line="115"
             column="13"/>
     </issue>
 
@@ -1284,7 +1270,7 @@
         errorLine2="            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~">
         <location
             file="src/main/res/values/strings.xml"
-            line="148"
+            line="149"
             column="13"/>
     </issue>
 
diff --git a/app/proguard-rules.pro b/app/proguard-rules.pro
index bfae18a3e..0a86f904d 100644
--- a/app/proguard-rules.pro
+++ b/app/proguard-rules.pro
@@ -73,10 +73,6 @@
 -keepattributes SourceFile,LineNumberTable
 -renamesourcefileattribute SourceFile
 
-# Bouncy Castle -- Keep EC
--keep class org.bouncycastle.jcajce.provider.asymmetric.EC$* { *; }
--keep class org.bouncycastle.jcajce.provider.asymmetric.ec.KeyPairGeneratorSpi$EC
-
 # remove all logging from production apk
 -assumenosideeffects class android.util.Log {
     public static *** getStackTraceString(...);
diff --git a/app/src/main/java/app/pachli/util/CryptoUtil.kt b/app/src/main/java/app/pachli/util/CryptoUtil.kt
index a179fb59e..e59283c7b 100644
--- a/app/src/main/java/app/pachli/util/CryptoUtil.kt
+++ b/app/src/main/java/app/pachli/util/CryptoUtil.kt
@@ -19,22 +19,14 @@ package app.pachli.util
 import android.util.Base64
 import java.security.KeyPairGenerator
 import java.security.SecureRandom
-import java.security.Security
-import org.bouncycastle.jce.ECNamedCurveTable
-import org.bouncycastle.jce.interfaces.ECPrivateKey
-import org.bouncycastle.jce.interfaces.ECPublicKey
-import org.bouncycastle.jce.provider.BouncyCastleProvider
+import java.security.interfaces.ECPublicKey
+import java.security.spec.ECGenParameterSpec
 
 object CryptoUtil {
     const val CURVE_PRIME256_V1 = "prime256v1"
 
     private const val BASE64_FLAGS = Base64.URL_SAFE or Base64.NO_PADDING or Base64.NO_WRAP
 
-    init {
-        Security.removeProvider(BouncyCastleProvider.PROVIDER_NAME)
-        Security.addProvider(BouncyCastleProvider())
-    }
-
     private fun secureRandomBytes(len: Int): ByteArray {
         val ret = ByteArray(len)
         SecureRandom.getInstance("SHA1PRNG").nextBytes(ret)
@@ -48,14 +40,54 @@ object CryptoUtil {
     data class EncodedKeyPair(val pubkey: String, val privKey: String)
 
     fun generateECKeyPair(curve: String): EncodedKeyPair {
-        val spec = ECNamedCurveTable.getParameterSpec(curve)
-        val gen = KeyPairGenerator.getInstance("EC", BouncyCastleProvider.PROVIDER_NAME)
+        val spec = ECGenParameterSpec(curve)
+        val gen = KeyPairGenerator.getInstance("EC")
         gen.initialize(spec)
         val keyPair = gen.genKeyPair()
         val pubKey = keyPair.public as ECPublicKey
-        val privKey = keyPair.private as ECPrivateKey
-        val encodedPubKey = Base64.encodeToString(pubKey.q.getEncoded(false), BASE64_FLAGS)
-        val encodedPrivKey = Base64.encodeToString(privKey.d.toByteArray(), BASE64_FLAGS)
+        val privKey = keyPair.private
+        val encodedPubKey = Base64.encodeToString(encodeP256Dh(pubKey), BASE64_FLAGS)
+        val encodedPrivKey = Base64.encodeToString(privKey.encoded, BASE64_FLAGS)
         return EncodedKeyPair(encodedPubKey, encodedPrivKey)
     }
+
+    /**
+     * Encodes the public key point P in X9.62 uncompressed format.
+     *
+     * This is section "2.3.3 Elliptic-Curve-Point-to-Octet-String Conversion" from
+     * https://www.secg.org/sec1-v2.pdf
+     */
+    // Code originally from https://github.com/tateisu/SubwayTooter/blob/main/base/src/main/java/jp/juggler/crypt/CryptUtils.kt
+    // under the Apache 2.0 license
+    private fun encodeP256Dh(key: ECPublicKey): ByteArray = key.run {
+        val bitsInByte = 8
+        val fieldSizeBytes = (params.order.bitLength() + bitsInByte - 1) / bitsInByte
+        return ByteArray(1 + 2 * fieldSizeBytes).also { dst ->
+            var offset = 0
+            dst[offset++] = 0x04 // 0x04 designates uncompressed format
+            w.affineX.toByteArray().let { x ->
+                when {
+                    x.size <= fieldSizeBytes ->
+                        System.arraycopy(x, 0, dst, offset + fieldSizeBytes - x.size, x.size)
+
+                    x.size == fieldSizeBytes + 1 && x[0].toInt() == 0 ->
+                        System.arraycopy(x, 1, dst, offset, fieldSizeBytes)
+
+                    else -> error("x value is too large")
+                }
+            }
+            offset += fieldSizeBytes
+            w.affineY.toByteArray().let { y ->
+                when {
+                    y.size <= fieldSizeBytes ->
+                        System.arraycopy(y, 0, dst, offset + fieldSizeBytes - y.size, y.size)
+
+                    y.size == fieldSizeBytes + 1 && y[0].toInt() == 0 ->
+                        System.arraycopy(y, 1, dst, offset, fieldSizeBytes)
+
+                    else -> error("y value is too large")
+                }
+            }
+        }
+    }
 }
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index d5c98c39b..94c20f0c0 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -31,7 +31,6 @@ app-update = "2.1.0"
 apollographql = "3.8.5"
 auto-service = "1.1.1"
 auto-service-ksp = "1.2.0"
-bouncycastle = "1.70"
 conscrypt = "2.5.3"
 coroutines = "1.9.0"
 coroutines-play-services = "1.9.0"
@@ -162,7 +161,6 @@ app-update-ktx = { module = "com.google.android.play:app-update-ktx", version.re
 apollo-runtime = { module = "com.apollographql.apollo3:apollo-runtime", version.ref = "apollographql" }
 auto-service-annotations = { module = "com.google.auto.service:auto-service-annotations", version.ref = "auto-service"}
 auto-service-ksp = { module = "dev.zacsweers.autoservice:auto-service-ksp", version.ref = "auto-service-ksp"}
-bouncycastle = { module = "org.bouncycastle:bcprov-jdk15on", version.ref = "bouncycastle" }
 conscrypt-android = { module = "org.conscrypt:conscrypt-android", version.ref = "conscrypt" }
 desugar_jdk_libs = { module = "com.android.tools:desugar_jdk_libs", version.ref = "desugar_jdk_libs" }
 diffx = { module = "org.pageseeder.diffx:pso-diffx", version.ref = "diffx" }
diff --git a/licenses/libraries/subway_tooter.json b/licenses/libraries/subway_tooter.json
new file mode 100644
index 000000000..f6dd973d0
--- /dev/null
+++ b/licenses/libraries/subway_tooter.json
@@ -0,0 +1,16 @@
+{
+    "uniqueId": "com.github.tateisu/SubwayTooter",
+    "developers": [
+        {
+            "name": "tateisu@mastodon.juggler.jp",
+            "organisationUrl": "https://github.com/tateisu/SubwayTooter"
+        }
+    ],
+    "artifactVersion": "f20f9fee8e",
+    "description": "X9.62 point encoding",
+    "name": "SubwayTooter code",
+    "licenses": [
+        "Apache_2_0"
+    ],
+    "website": "https://subwaytooter.hatenadiary.jp/"
+}