diff --git a/ext/pgp_rb/Cargo.lock b/ext/pgp_rb/Cargo.lock
index fbda522..4e0bfe8 100644
--- a/ext/pgp_rb/Cargo.lock
+++ b/ext/pgp_rb/Cargo.lock
@@ -425,22 +425,6 @@ dependencies = [
  "subtle",
 ]
 
-[[package]]
-name = "dsa"
-version = "0.6.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "48bc224a9084ad760195584ce5abb3c2c34a225fa312a128ad245a6b412b7689"
-dependencies = [
- "digest",
- "num-bigint-dig",
- "num-traits",
- "pkcs8",
- "rfc6979",
- "sha2",
- "signature",
- "zeroize",
-]
-
 [[package]]
 name = "ecdsa"
 version = "0.16.9"
@@ -506,12 +490,6 @@ dependencies = [
  "zeroize",
 ]
 
-[[package]]
-name = "equivalent"
-version = "1.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5443807d6dff69373d433ab9ef5378ad8df50ca6298caf15de6e52e24aaf54d5"
-
 [[package]]
 name = "ff"
 version = "0.13.0"
@@ -583,12 +561,6 @@ dependencies = [
  "subtle",
 ]
 
-[[package]]
-name = "hashbrown"
-version = "0.14.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "290f1a1d9242c78d09ce40a5e87e7554ee637af1351968159f4952f028f75604"
-
 [[package]]
 name = "hex"
 version = "0.4.3"
@@ -651,16 +623,6 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
 
-[[package]]
-name = "indexmap"
-version = "2.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "233cf39063f058ea2caae4091bf4a3ef70a653afbc026f5c4a4135d114e3c177"
-dependencies = [
- "equivalent",
- "hashbrown",
-]
-
 [[package]]
 name = "inout"
 version = "0.1.3"
@@ -670,12 +632,6 @@ dependencies = [
  "generic-array",
 ]
 
-[[package]]
-name = "iter-read"
-version = "1.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a598c1abae8e3456ebda517868b254b6bc2a9bb6501ffd5b9d0875bf332e048b"
-
 [[package]]
 name = "itertools"
 version = "0.12.1"
@@ -694,20 +650,6 @@ dependencies = [
  "wasm-bindgen",
 ]
 
-[[package]]
-name = "k256"
-version = "0.13.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "956ff9b67e26e1a6a866cb758f12c6f8746208489e3e4a4b5580802f2f0a587b"
-dependencies = [
- "cfg-if",
- "ecdsa",
- "elliptic-curve",
- "once_cell",
- "sha2",
- "signature",
-]
-
 [[package]]
 name = "keccak"
 version = "0.1.5"
@@ -840,6 +782,17 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "num-derive"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed3955f1a9c7c0c15e092f9c887db08b1fc683305fdf6eb6684f22555355e202"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.50",
+]
+
 [[package]]
 name = "num-integer"
 version = "0.1.46"
@@ -870,27 +823,6 @@ dependencies = [
  "libm",
 ]
 
-[[package]]
-name = "num_enum"
-version = "0.7.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "02339744ee7253741199f897151b38e72257d13802d4ee837285cc2990a90845"
-dependencies = [
- "num_enum_derive",
-]
-
-[[package]]
-name = "num_enum_derive"
-version = "0.7.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "681030a937600a36906c185595136d26abfebb4aa9c65701cefcaf8578bb982b"
-dependencies = [
- "proc-macro-crate",
- "proc-macro2",
- "quote",
- "syn 2.0.50",
-]
-
 [[package]]
 name = "once_cell"
 version = "1.19.0"
@@ -932,9 +864,9 @@ dependencies = [
 
 [[package]]
 name = "pgp"
-version = "0.11.0"
+version = "0.10.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "031fa1e28c4cb54c90502ef0642a44ef10ec8349349ebe6372089f1b1ef4f297"
+checksum = "27e1f8e085bfa9b85763fe3ddaacbe90a09cd847b3833129153a6cb063bbe132"
 dependencies = [
  "aes",
  "base64",
@@ -949,27 +881,23 @@ dependencies = [
  "cfb-mode",
  "chrono",
  "cipher",
- "const-oid",
  "crc24",
  "curve25519-dalek",
  "derive_builder",
  "des",
  "digest",
- "dsa",
  "ed25519-dalek",
  "elliptic-curve",
  "flate2",
  "generic-array",
  "hex",
  "idea",
- "iter-read",
- "k256",
  "log",
  "md-5",
  "nom",
  "num-bigint-dig",
+ "num-derive",
  "num-traits",
- "num_enum",
  "p256",
  "p384",
  "rand",
@@ -992,6 +920,7 @@ version = "1.0.0"
 dependencies = [
  "base64",
  "magnus",
+ "num-traits",
  "pgp",
  "rand",
 ]
@@ -1038,15 +967,6 @@ dependencies = [
  "elliptic-curve",
 ]
 
-[[package]]
-name = "proc-macro-crate"
-version = "3.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6d37c51ca738a55da99dc0c4a34860fd675453b8b36209178c2249bb13651284"
-dependencies = [
- "toml_edit",
-]
-
 [[package]]
 name = "proc-macro2"
 version = "1.0.78"
@@ -1390,23 +1310,6 @@ dependencies = [
  "syn 2.0.50",
 ]
 
-[[package]]
-name = "toml_datetime"
-version = "0.6.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3550f4e9685620ac18a50ed434eb3aec30db8ba93b0287467bca5826ea25baf1"
-
-[[package]]
-name = "toml_edit"
-version = "0.21.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a8534fd7f78b5405e860340ad6575217ce99f38d4d5c8f2442cb5ecb50090e1"
-dependencies = [
- "indexmap",
- "toml_datetime",
- "winnow",
-]
-
 [[package]]
 name = "twofish"
 version = "0.7.1"
@@ -1626,15 +1529,6 @@ version = "0.52.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0770833d60a970638e989b3fa9fd2bb1aaadcf88963d1659fd7d9990196ed2d6"
 
-[[package]]
-name = "winnow"
-version = "0.5.40"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f593a95398737aeed53e489c785df13f3618e41dbcd6718c6addbf1395aa6876"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "x25519-dalek"
 version = "2.0.1"
diff --git a/ext/pgp_rb/Cargo.toml b/ext/pgp_rb/Cargo.toml
index 422ba3b..f1680a6 100644
--- a/ext/pgp_rb/Cargo.toml
+++ b/ext/pgp_rb/Cargo.toml
@@ -4,10 +4,11 @@ version = "1.0.0"
 edition = "2021"
 
 [dependencies]
-pgp = "0.11.0"
+pgp = "0.10.2"
 rand = "0.8.5"
 magnus = { git = "https://github.com/matsadler/magnus.git", default_features = false }
 base64 = "0.21.7"
+num-traits = "0.2.18"
 
 [lib]
 crate-type = ["cdylib"]
diff --git a/ext/pgp_rb/src/lib.rs b/ext/pgp_rb/src/lib.rs
index 9194624..f97800f 100644
--- a/ext/pgp_rb/src/lib.rs
+++ b/ext/pgp_rb/src/lib.rs
@@ -7,8 +7,12 @@ use magnus::{
 };
 
 use pgp::composed::{Message, Deserializable, SignedPublicKey};
+use pgp::crypto::public_key::PublicKeyAlgorithm;
 use pgp::crypto::sym::SymmetricKeyAlgorithm;
+
+use pgp::types::KeyVersion;
 use pgp::types::KeyTrait;
+use num_traits::cast::FromPrimitive;
 
 use std::io::Cursor;
 use base64::{engine::general_purpose, Engine as _};
@@ -68,7 +72,29 @@ impl PgpPublicKey {
     }
 
     fn algorithm(rb_self: &PgpPublicKey) -> u8 {
-        u8::from(rb_self.signed_public_key.algorithm())
+        match rb_self.signed_public_key.algorithm() {
+            PublicKeyAlgorithm::RSA => 1,
+            PublicKeyAlgorithm::RSAEncrypt => 2,
+            PublicKeyAlgorithm::RSASign => 3,
+            PublicKeyAlgorithm::ElgamalSign => 16,
+            PublicKeyAlgorithm::DSA => 17,
+            PublicKeyAlgorithm::ECDH => 18,
+            PublicKeyAlgorithm::ECDSA => 19,
+            PublicKeyAlgorithm::Elgamal => 20,
+            PublicKeyAlgorithm::DiffieHellman => 21,
+            PublicKeyAlgorithm::EdDSA => 22,
+            PublicKeyAlgorithm::Private100 => 100,
+            PublicKeyAlgorithm::Private101 => 101,
+            PublicKeyAlgorithm::Private102 => 102,
+            PublicKeyAlgorithm::Private103 => 103,
+            PublicKeyAlgorithm::Private104 => 104,
+            PublicKeyAlgorithm::Private105 => 105,
+            PublicKeyAlgorithm::Private106 => 106,
+            PublicKeyAlgorithm::Private107 => 107,
+            PublicKeyAlgorithm::Private108 => 108,
+            PublicKeyAlgorithm::Private109 => 109,
+            PublicKeyAlgorithm::Private110 => 110
+        }
     }
 
     fn is_signing_key(rb_self: &PgpPublicKey) -> bool {
@@ -80,7 +106,12 @@ impl PgpPublicKey {
     }
 
     fn version(rb_self: &PgpPublicKey) -> u8 {
-        u8::from(rb_self.signed_public_key.primary_key.version())
+        match rb_self.signed_public_key.primary_key.version() {
+            KeyVersion::V2 => 2,
+            KeyVersion::V3 => 3,
+            KeyVersion::V4 => 4,
+            KeyVersion::V5 => 5
+        }
     }
 
     fn created_at(ruby: &Ruby, rb_self: &PgpPublicKey) -> Result<Time, Error> {
@@ -104,18 +135,16 @@ impl PgpPublicKey {
 
     fn encrypt_with_algorithm(ruby: &Ruby, rb_self: &PgpPublicKey, input: String, algorithm: Integer) -> Result<String, Error> {
         let alg = match algorithm.to_u8() {
-            Ok(v) => SymmetricKeyAlgorithm::from(v),
+            Ok(v) => match SymmetricKeyAlgorithm::from_u8(v) {
+                Some(a) => a,
+                None => {
+                    let error_message = format!("unsupported algorithm: {}", algorithm);
+                    return Err(Error::new(ruby.exception_arg_error(), error_message))
+                }
+            },
             Err(e) => return Err(e)
         };
 
-        match alg {
-            SymmetricKeyAlgorithm::Other(_) => {
-                let error_message = format!("unsupported algorithm: {}", algorithm);
-                return Err(Error::new(ruby.exception_arg_error(), error_message))
-            },
-            _ => {}
-        }
-
         let msg = Message::new_literal("", &input.to_string());
         let encrypted = msg.encrypt_to_keys(
             &mut rand::thread_rng(),