diff --git a/trunk/PKGBUILD b/trunk/PKGBUILD
index e188853..24f08d7 100644
--- a/trunk/PKGBUILD
+++ b/trunk/PKGBUILD
@@ -11,17 +11,23 @@ license=(MIT)
 makedepends=(gtk3 intltool curl qt5-base libevent systemd qt5-tools libappindicator-gtk3 libnatpmp miniupnpc cmake)
 source=(https://github.com/transmission/transmission-releases/raw/master/transmission-${pkgver}.tar.xz
         transmission-3.00-tarball-missing-files.patch # https://github.com/transmission/transmission/issues/1248
+        transmission-3.00-arc4.patch # based on https://github.com/transmission/transmission/commit/a459e5e11b2d2524b649f7487368de30c8d2af21
+        arc4-1.0.0.tar.gz::https://github.com/transmission/arc4/archive/refs/tags/v1.0.0.tar.gz
         transmission-cli.sysusers
         transmission-cli.tmpfiles)
 sha256sums=('9144652fe742f7f7dd6657716e378da60b751aaeda8bef8344b3eefc4db255f2'
             '25717d638b84f368ae3e8ba17f26a17eb1f5767c1218946c7c03ee9fbaaf9b5d'
+            '8f07c225959fe11ea473cc6012eba5dad603b70b2c1a9ac5617499424af1655c'
+            'dd098dd34be65c81e8dd1e984e031b66346350909132b3b5af80e76d60aa55f1'
             '641310fb0590d40e00bea1b5b9c843953ab78edf019109f276be9c6a7bdaf5b2'
             '1266032bb07e47d6bcdc7dabd74df2557cc466c33bf983a5881316a4cc098451')
 
 prepare() {
   cd $pkgbase-$pkgver
+  mv ../arc4-1.0.0 third-party/arc4
 
   patch -p1 -i ../transmission-3.00-tarball-missing-files.patch
+  patch -p1 -i ../transmission-3.00-arc4.patch
 
   sed -i '/^Icon=/ s/$/-qt/' qt/transmission-qt.desktop
 }
@@ -30,10 +36,16 @@ build() {
   cmake -B build -S $pkgbase-$pkgver \
         -D CMAKE_INSTALL_PREFIX='/usr' \
         -D ENABLE_CLI=TRUE \
+        -D ENABLE_TESTS=TRUE \
         -Wno-dev
   cmake --build build
 }
 
+check() {
+    cd build
+    ctest --output-on-failure
+}
+
 package_transmission-cli() {
   pkgdesc='Fast, easy, and free BitTorrent client (CLI tools, daemon)'
   depends=(curl libevent libnatpmp miniupnpc systemd)
diff --git a/trunk/transmission-3.00-arc4.patch b/trunk/transmission-3.00-arc4.patch
new file mode 100644
index 0000000..712db9f
--- /dev/null
+++ b/trunk/transmission-3.00-arc4.patch
@@ -0,0 +1,445 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 62bf87be7..0607620d8 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -334,6 +334,8 @@ endif()
+ 
+ tr_add_external_auto_library(B64 libb64 b64)
+ 
++add_subdirectory(third-party/arc4)
++
+ if(WITH_INOTIFY)
+     tr_get_required_flag(WITH_INOTIFY INOTIFY_IS_REQUIRED)
+ 
+diff --git a/libtransmission/CMakeLists.txt b/libtransmission/CMakeLists.txt
+index 672cd0e0b..62b68b948 100644
+--- a/libtransmission/CMakeLists.txt
++++ b/libtransmission/CMakeLists.txt
+@@ -274,6 +274,7 @@ target_link_libraries(${TR_NAME}
+     ${LIBINTL_LIBRARY}
+     ${LIBM_LIBRARY}
+     ${TR_NETWORK_LIBRARIES}
++    arc4::arc4
+ )
+ 
+ if(ICONV_FOUND)
+diff --git a/libtransmission/crypto-test-ref.h b/libtransmission/crypto-test-ref.h
+index d809ebb0b..6ab8b11ed 100644
+--- a/libtransmission/crypto-test-ref.h
++++ b/libtransmission/crypto-test-ref.h
+@@ -16,7 +16,6 @@
+ #define KEY_LEN KEY_LEN_
+ 
+ #define tr_sha1_ctx_t tr_sha1_ctx_t_
+-#define tr_rc4_ctx_t tr_rc4_ctx_t_
+ #define tr_dh_ctx_t tr_dh_ctx_t_
+ #define tr_dh_secret_t tr_dh_secret_t_
+ #define tr_ssl_ctx_t tr_ssl_ctx_t_
+@@ -39,10 +38,6 @@
+ #define tr_sha1_init tr_sha1_init_
+ #define tr_sha1_update tr_sha1_update_
+ #define tr_sha1_final tr_sha1_final_
+-#define tr_rc4_new tr_rc4_new_
+-#define tr_rc4_free tr_rc4_free_
+-#define tr_rc4_set_key tr_rc4_set_key_
+-#define tr_rc4_process tr_rc4_process_
+ #define tr_dh_new tr_dh_new_
+ #define tr_dh_free tr_dh_free_
+ #define tr_dh_make_key tr_dh_make_key_
+@@ -80,7 +75,6 @@
+ #undef KEY_LEN_
+ 
+ #undef tr_sha1_ctx_t
+-#undef tr_rc4_ctx_t
+ #undef tr_dh_ctx_t
+ #undef tr_dh_secret_t
+ #undef tr_ssl_ctx_t
+@@ -103,10 +97,6 @@
+ #undef tr_sha1_init
+ #undef tr_sha1_update
+ #undef tr_sha1_final
+-#undef tr_rc4_new
+-#undef tr_rc4_free
+-#undef tr_rc4_set_key
+-#undef tr_rc4_process
+ #undef tr_dh_new
+ #undef tr_dh_free
+ #undef tr_dh_make_key
+@@ -137,7 +127,6 @@
+ #define KEY_LEN_ KEY_LEN
+ 
+ #define tr_sha1_ctx_t_ tr_sha1_ctx_t
+-#define tr_rc4_ctx_t_ tr_rc4_ctx_t
+ #define tr_dh_ctx_t_ tr_dh_ctx_t
+ #define tr_dh_secret_t_ tr_dh_secret_t
+ #define tr_ssl_ctx_t_ tr_ssl_ctx_t
+@@ -160,10 +149,6 @@
+ #define tr_sha1_init_ tr_sha1_init
+ #define tr_sha1_update_ tr_sha1_update
+ #define tr_sha1_final_ tr_sha1_final
+-#define tr_rc4_new_ tr_rc4_new
+-#define tr_rc4_free_ tr_rc4_free
+-#define tr_rc4_set_key_ tr_rc4_set_key
+-#define tr_rc4_process_ tr_rc4_process
+ #define tr_dh_new_ tr_dh_new
+ #define tr_dh_free_ tr_dh_free
+ #define tr_dh_make_key_ tr_dh_make_key
+diff --git a/libtransmission/crypto-utils-cyassl.c b/libtransmission/crypto-utils-cyassl.c
+index 60659ff85..a95bfb53d 100644
+--- a/libtransmission/crypto-utils-cyassl.c
++++ b/libtransmission/crypto-utils-cyassl.c
+@@ -19,7 +19,6 @@
+ #define API_VERSION_HEX LIBCYASSL_VERSION_HEX
+ #endif
+ 
+-#include API_HEADER_CRYPT(arc4.h)
+ #include API_HEADER_CRYPT(dh.h)
+ #include API_HEADER_CRYPT(error-crypt.h)
+ #include API_HEADER_CRYPT(random.h)
+@@ -166,44 +165,6 @@ bool tr_sha1_final(tr_sha1_ctx_t handle, uint8_t* hash)
+ /***
+ ****
+ ***/
+-
+-tr_rc4_ctx_t tr_rc4_new(void)
+-{
+-    return tr_new0(Arc4, 1);
+-}
+-
+-void tr_rc4_free(tr_rc4_ctx_t handle)
+-{
+-    tr_free(handle);
+-}
+-
+-void tr_rc4_set_key(tr_rc4_ctx_t handle, uint8_t const* key, size_t key_length)
+-{
+-    TR_ASSERT(handle != NULL);
+-    TR_ASSERT(key != NULL);
+-
+-    API(Arc4SetKey)(handle, key, key_length);
+-}
+-
+-void tr_rc4_process(tr_rc4_ctx_t handle, void const* input, void* output, size_t length)
+-{
+-    TR_ASSERT(handle != NULL);
+-
+-    if (length == 0)
+-    {
+-        return;
+-    }
+-
+-    TR_ASSERT(input != NULL);
+-    TR_ASSERT(output != NULL);
+-
+-    API(Arc4Process)(handle, output, input, length);
+-}
+-
+-/***
+-****
+-***/
+-
+ tr_dh_ctx_t tr_dh_new(uint8_t const* prime_num, size_t prime_num_length, uint8_t const* generator_num,
+     size_t generator_num_length)
+ {
+diff --git a/libtransmission/crypto-utils-openssl.c b/libtransmission/crypto-utils-openssl.c
+index 45fd71913..ca6909e48 100644
+--- a/libtransmission/crypto-utils-openssl.c
++++ b/libtransmission/crypto-utils-openssl.c
+@@ -182,59 +182,6 @@ static void openssl_evp_cipher_context_free(EVP_CIPHER_CTX* handle)
+ 
+ #endif
+ 
+-tr_rc4_ctx_t tr_rc4_new(void)
+-{
+-    EVP_CIPHER_CTX* handle = EVP_CIPHER_CTX_new();
+-
+-    if (check_result(EVP_CipherInit_ex(handle, EVP_rc4(), NULL, NULL, NULL, -1)))
+-    {
+-        return handle;
+-    }
+-
+-    EVP_CIPHER_CTX_free(handle);
+-    return NULL;
+-}
+-
+-void tr_rc4_free(tr_rc4_ctx_t handle)
+-{
+-    if (handle == NULL)
+-    {
+-        return;
+-    }
+-
+-    EVP_CIPHER_CTX_free(handle);
+-}
+-
+-void tr_rc4_set_key(tr_rc4_ctx_t handle, uint8_t const* key, size_t key_length)
+-{
+-    TR_ASSERT(handle != NULL);
+-    TR_ASSERT(key != NULL);
+-
+-    if (!check_result(EVP_CIPHER_CTX_set_key_length(handle, key_length)))
+-    {
+-        return;
+-    }
+-
+-    check_result(EVP_CipherInit_ex(handle, NULL, NULL, key, NULL, -1));
+-}
+-
+-void tr_rc4_process(tr_rc4_ctx_t handle, void const* input, void* output, size_t length)
+-{
+-    TR_ASSERT(handle != NULL);
+-
+-    if (length == 0)
+-    {
+-        return;
+-    }
+-
+-    TR_ASSERT(input != NULL);
+-    TR_ASSERT(output != NULL);
+-
+-    int output_length;
+-
+-    check_result(EVP_CipherUpdate(handle, output, &output_length, input, length));
+-}
+-
+ /***
+ ****
+ ***/
+diff --git a/libtransmission/crypto-utils-polarssl.c b/libtransmission/crypto-utils-polarssl.c
+index 889332a3a..8f9afeea3 100644
+--- a/libtransmission/crypto-utils-polarssl.c
++++ b/libtransmission/crypto-utils-polarssl.c
+@@ -186,53 +186,6 @@ bool tr_sha1_final(tr_sha1_ctx_t handle, uint8_t* hash)
+ ****
+ ***/
+ 
+-tr_rc4_ctx_t tr_rc4_new(void)
+-{
+-    api_arc4_context* handle = tr_new0(api_arc4_context, 1);
+-
+-#if API_VERSION_NUMBER >= 0x01030800
+-    API(arc4_init)(handle);
+-#endif
+-
+-    return handle;
+-}
+-
+-void tr_rc4_free(tr_rc4_ctx_t handle)
+-{
+-#if API_VERSION_NUMBER >= 0x01030800
+-    API(arc4_free)(handle);
+-#endif
+-
+-    tr_free(handle);
+-}
+-
+-void tr_rc4_set_key(tr_rc4_ctx_t handle, uint8_t const* key, size_t key_length)
+-{
+-    TR_ASSERT(handle != NULL);
+-    TR_ASSERT(key != NULL);
+-
+-    API(arc4_setup)(handle, key, key_length);
+-}
+-
+-void tr_rc4_process(tr_rc4_ctx_t handle, void const* input, void* output, size_t length)
+-{
+-    TR_ASSERT(handle != NULL);
+-
+-    if (length == 0)
+-    {
+-        return;
+-    }
+-
+-    TR_ASSERT(input != NULL);
+-    TR_ASSERT(output != NULL);
+-
+-    API(arc4_crypt)(handle, length, input, output);
+-}
+-
+-/***
+-****
+-***/
+-
+ tr_dh_ctx_t tr_dh_new(uint8_t const* prime_num, size_t prime_num_length, uint8_t const* generator_num,
+     size_t generator_num_length)
+ {
+diff --git a/libtransmission/crypto-utils.c b/libtransmission/crypto-utils.c
+index 329adc009..bc6ae0e72 100644
+--- a/libtransmission/crypto-utils.c
++++ b/libtransmission/crypto-utils.c
+@@ -10,6 +10,7 @@
+ #include <stdlib.h> /* abs(), srand(), rand() */
+ #include <string.h> /* memcpy(), memmove(), memset(), strcmp(), strlen() */
+ 
++#include <arc4.h>
+ #include <b64/cdecode.h>
+ #include <b64/cencode.h>
+ 
+diff --git a/libtransmission/crypto-utils.h b/libtransmission/crypto-utils.h
+index 7ae3cee86..9c223d00e 100644
+--- a/libtransmission/crypto-utils.h
++++ b/libtransmission/crypto-utils.h
+@@ -27,8 +27,6 @@ extern "C"
+ 
+ /** @brief Opaque SHA1 context type. */
+ typedef void* tr_sha1_ctx_t;
+-/** @brief Opaque RC4 context type. */
+-typedef void* tr_rc4_ctx_t;
+ /** @brief Opaque DH context type. */
+ typedef void* tr_dh_ctx_t;
+ /** @brief Opaque DH secret key type. */
+@@ -60,26 +58,6 @@ bool tr_sha1_update(tr_sha1_ctx_t handle, void const* data, size_t data_length);
+  */
+ bool tr_sha1_final(tr_sha1_ctx_t handle, uint8_t* hash);
+ 
+-/**
+- * @brief Allocate and initialize new RC4 cipher context.
+- */
+-tr_rc4_ctx_t tr_rc4_new(void);
+-
+-/**
+- * @brief Free RC4 cipher context.
+- */
+-void tr_rc4_free(tr_rc4_ctx_t handle);
+-
+-/**
+- * @brief Set RC4 cipher key.
+- */
+-void tr_rc4_set_key(tr_rc4_ctx_t handle, uint8_t const* key, size_t key_length);
+-
+-/**
+- * @brief Process memory block with RC4 cipher.
+- */
+-void tr_rc4_process(tr_rc4_ctx_t handle, void const* input, void* output, size_t length);
+-
+ /**
+  * @brief Allocate and initialize new Diffie-Hellman (DH) key exchange context.
+  */
+diff --git a/libtransmission/crypto.c b/libtransmission/crypto.c
+index e64b998df..289f6dbb9 100644
+--- a/libtransmission/crypto.c
++++ b/libtransmission/crypto.c
+@@ -8,6 +8,8 @@
+ 
+ #include <string.h> /* memcpy(), memmove(), memset() */
+ 
++#include <arc4.h>
++
+ #include "transmission.h"
+ #include "crypto.h"
+ #include "crypto-utils.h"
+@@ -64,8 +66,8 @@ void tr_cryptoDestruct(tr_crypto* crypto)
+ {
+     tr_dh_secret_free(crypto->mySecret);
+     tr_dh_free(crypto->dh);
+-    tr_rc4_free(crypto->enc_key);
+-    tr_rc4_free(crypto->dec_key);
++    tr_free(crypto->enc_key);
++    tr_free(crypto->dec_key);
+ }
+ 
+ /**
+@@ -90,36 +92,27 @@ uint8_t const* tr_cryptoGetMyPublicKey(tr_crypto const* crypto, int* setme_len)
+ ***
+ **/
+ 
+-static void initRC4(tr_crypto* crypto, tr_rc4_ctx_t* setme, char const* key)
++static void init_rc4(tr_crypto const* crypto, struct arc4_context** setme, char const* key)
+ {
+     TR_ASSERT(crypto->torrentHashIsSet);
+ 
+     if (*setme == NULL)
+     {
+-        *setme = tr_rc4_new();
++        *setme = tr_new0(struct arc4_context, 1);
+     }
+ 
+     uint8_t buf[SHA_DIGEST_LENGTH];
+ 
+     if (tr_cryptoSecretKeySha1(crypto, key, 4, crypto->torrentHash, SHA_DIGEST_LENGTH, buf))
+     {
+-        tr_rc4_set_key(*setme, buf, SHA_DIGEST_LENGTH);
++        arc4_init(*setme, buf, SHA_DIGEST_LENGTH);
++        arc4_discard(*setme, 1024);
+     }
+ }
+ 
+-void tr_cryptoDecryptInit(tr_crypto* crypto)
+-{
+-    uint8_t discard[1024];
+-    char const* txt = crypto->isIncoming ? "keyA" : "keyB";
+-
+-    initRC4(crypto, &crypto->dec_key, txt);
+-    tr_rc4_process(crypto->dec_key, discard, discard, sizeof(discard));
+-}
+-
+-void tr_cryptoDecrypt(tr_crypto* crypto, size_t buf_len, void const* buf_in, void* buf_out)
++static void crypt_rc4(struct arc4_context* key, size_t buf_len, void const* buf_in, void* buf_out)
+ {
+-    /* FIXME: someone calls this function with uninitialized key */
+-    if (crypto->dec_key == NULL)
++    if (key == NULL)
+     {
+         if (buf_in != buf_out)
+         {
+@@ -129,32 +122,27 @@ void tr_cryptoDecrypt(tr_crypto* crypto, size_t buf_len, void const* buf_in, voi
+         return;
+     }
+ 
+-    tr_rc4_process(crypto->dec_key, buf_in, buf_out, buf_len);
++    arc4_process(key, buf_in, buf_out, buf_len);
+ }
+ 
+-void tr_cryptoEncryptInit(tr_crypto* crypto)
++void tr_cryptoDecryptInit(tr_crypto* crypto)
+ {
+-    uint8_t discard[1024];
+-    char const* txt = crypto->isIncoming ? "keyB" : "keyA";
+-
+-    initRC4(crypto, &crypto->enc_key, txt);
+-    tr_rc4_process(crypto->enc_key, discard, discard, sizeof(discard));
++    init_rc4(crypto, &crypto->dec_key, crypto->isIncoming ? "keyA" : "keyB"); // lgtm[cpp/weak-cryptographic-algorithm]
+ }
+ 
+-void tr_cryptoEncrypt(tr_crypto* crypto, size_t buf_len, void const* buf_in, void* buf_out)
++void tr_cryptoDecrypt(tr_crypto* crypto, size_t buf_len, void const* buf_in, void* buf_out)
+ {
+-    /* FIXME: someone calls this function with uninitialized key */
+-    if (crypto->enc_key == NULL)
+-    {
+-        if (buf_in != buf_out)
+-        {
+-            memmove(buf_out, buf_in, buf_len);
+-        }
++    crypt_rc4(crypto->dec_key, buf_len, buf_in, buf_out); // lgtm[cpp/weak-cryptographic-algorithm]
++}
+ 
+-        return;
+-    }
++void tr_cryptoEncryptInit(tr_crypto* crypto)
++{
++    init_rc4(crypto, &crypto->enc_key, crypto->isIncoming ? "keyB" : "keyA"); // lgtm[cpp/weak-cryptographic-algorithm]
++}
+ 
+-    tr_rc4_process(crypto->enc_key, buf_in, buf_out, buf_len);
++void tr_cryptoEncrypt(tr_crypto* crypto, size_t buf_len, void const* buf_in, void* buf_out)
++{
++    crypt_rc4(crypto->enc_key, buf_len, buf_in, buf_out); // lgtm[cpp/weak-cryptographic-algorithm]
+ }
+ 
+ bool tr_cryptoSecretKeySha1(tr_crypto const* crypto, void const* prepend_data, size_t prepend_data_size,
+diff --git a/libtransmission/crypto.h b/libtransmission/crypto.h
+index 7e6c85d42..7fe14f768 100644
+--- a/libtransmission/crypto.h
++++ b/libtransmission/crypto.h
+@@ -31,8 +31,8 @@ enum
+ /** @brief Holds state information for encrypted peer communications */
+ typedef struct
+ {
+-    tr_rc4_ctx_t dec_key;
+-    tr_rc4_ctx_t enc_key;
++    struct arc4_context* dec_key;
++    struct arc4_context* enc_key;
+     tr_dh_ctx_t dh;
+     uint8_t myPublicKey[KEY_LEN];
+     tr_dh_secret_t mySecret;