diff --git a/zebra-chain/proptest-regressions/orchard/keys/tests.txt b/zebra-chain/proptest-regressions/orchard/keys/tests.txt
new file mode 100644
index 00000000..6ae352ec
--- /dev/null
+++ b/zebra-chain/proptest-regressions/orchard/keys/tests.txt
@@ -0,0 +1,7 @@
+# Seeds for failure cases proptest has generated in the past. It is
+# automatically read and these particular cases re-run before any
+# novel cases are generated.
+#
+# It is recommended to check this file in to source control so that
+# everyone who runs the test benefits from these saved cases.
+cc 8ba80e3da74dc90c627f620bed08c47e7a13bb2e7762aad6e8c8f362237aed1b # shrinks to spending_key = SpendingKey { network: Mainnet, bytes: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] }
diff --git a/zebra-chain/src/orchard/keys.rs b/zebra-chain/src/orchard/keys.rs
index 4a210ae2..6975217d 100644
--- a/zebra-chain/src/orchard/keys.rs
+++ b/zebra-chain/src/orchard/keys.rs
@@ -11,11 +11,10 @@ use std::{
     convert::{From, Into, TryFrom, TryInto},
     fmt,
     io::{self, Write},
-    str::FromStr,
 };
 
 use aes::Aes256;
-use bech32::{self, FromBase32, ToBase32, Variant};
+use bech32::{self, ToBase32, Variant};
 use bitvec::prelude::*;
 use fpe::ff1::{BinaryNumeralString, FF1};
 use group::{Group, GroupEncoding};
@@ -161,31 +160,6 @@ impl fmt::Display for SpendingKey {
     }
 }
 
-impl FromStr for SpendingKey {
-    type Err = SerializationError;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        match bech32::decode(s) {
-            Ok((hrp, bytes, Variant::Bech32)) => {
-                let decoded = Vec::<u8>::from_base32(&bytes).unwrap();
-
-                let mut decoded_bytes = [0u8; 32];
-                decoded_bytes[..].copy_from_slice(&decoded[0..32]);
-
-                Ok(SpendingKey {
-                    network: match hrp.as_str() {
-                        sk_hrp::MAINNET => Network::Mainnet,
-                        sk_hrp::TESTNET => Network::Testnet,
-                        _ => return Err(SerializationError::Parse("unknown network")),
-                    },
-                    bytes: decoded_bytes,
-                })
-            }
-            _ => Err(SerializationError::Parse("bech32 decoding error")),
-        }
-    }
-}
-
 impl SpendingKey {
     /// Generate a new `SpendingKey`.
     ///
@@ -493,30 +467,6 @@ impl From<FullViewingKey> for IncomingViewingKey {
     }
 }
 
-impl FromStr for IncomingViewingKey {
-    type Err = SerializationError;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        match bech32::decode(s) {
-            Ok((hrp, bytes, Variant::Bech32)) => {
-                let decoded = Vec::<u8>::from_base32(&bytes).unwrap();
-
-                let mut scalar_bytes = [0u8; 32];
-                scalar_bytes[..].copy_from_slice(&decoded[0..32]);
-
-                Ok(IncomingViewingKey {
-                    network: match hrp.as_str() {
-                        ivk_hrp::MAINNET => Network::Mainnet,
-                        _ => Network::Testnet,
-                    },
-                    scalar: pallas::Scalar::from_bytes(&scalar_bytes).unwrap(),
-                })
-            }
-            _ => Err(SerializationError::Parse("bech32 decoding error")),
-        }
-    }
-}
-
 impl PartialEq<[u8; 32]> for IncomingViewingKey {
     fn eq(&self, other: &[u8; 32]) -> bool {
         self.scalar.to_bytes() == *other
@@ -588,33 +538,6 @@ impl fmt::Display for FullViewingKey {
     }
 }
 
-impl FromStr for FullViewingKey {
-    type Err = SerializationError;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        match bech32::decode(s) {
-            Ok((hrp, bytes, Variant::Bech32)) => {
-                let mut decoded_bytes = io::Cursor::new(Vec::<u8>::from_base32(&bytes).unwrap());
-
-                let ak_bytes = decoded_bytes.read_32_bytes()?;
-                let nk_bytes = decoded_bytes.read_32_bytes()?;
-                let rivk_bytes = decoded_bytes.read_32_bytes()?;
-
-                Ok(FullViewingKey {
-                    network: match hrp.as_str() {
-                        fvk_hrp::MAINNET => Network::Mainnet,
-                        _ => Network::Testnet,
-                    },
-                    spend_validating_key: SpendValidatingKey::from(ak_bytes),
-                    nullifier_deriving_key: NullifierDerivingKey::from(nk_bytes),
-                    ivk_commit_randomness: IvkCommitRandomness::try_from(rivk_bytes).unwrap(),
-                })
-            }
-            _ => Err(SerializationError::Parse("bech32 decoding error")),
-        }
-    }
-}
-
 impl FullViewingKey {
     /// [4.2.3]: https://zips.z.cash/protocol/nu5.pdf#orchardkeycomponents
     #[allow(non_snake_case)]
diff --git a/zebra-chain/src/orchard/keys/tests.rs b/zebra-chain/src/orchard/keys/tests.rs
index 84ec4abc..93e62047 100644
--- a/zebra-chain/src/orchard/keys/tests.rs
+++ b/zebra-chain/src/orchard/keys/tests.rs
@@ -30,13 +30,9 @@ impl Arbitrary for TransmissionKey {
 proptest! {
 
     #[test]
-    fn string_roundtrips(spending_key in any::<SpendingKey>()) {
+    fn generate_keys(spending_key in any::<SpendingKey>()) {
         zebra_test::init();
 
-        let sk_string = spending_key.to_string();
-        let spending_key_2: SpendingKey = sk_string.parse().unwrap();
-        prop_assert_eq![spending_key, spending_key_2];
-
         let spend_authorizing_key = SpendAuthorizingKey::from(spending_key);
 
         let spend_validating_key = SpendValidatingKey::from(spend_authorizing_key);
@@ -50,17 +46,9 @@ proptest! {
             ivk_commit_randomness,
         };
 
-        let fvk_string = full_viewing_key.to_string();
-        let full_viewing_key_2: FullViewingKey = fvk_string.parse().unwrap();
-        prop_assert_eq![full_viewing_key, full_viewing_key_2];
-
         let diversifier_key = DiversifierKey::from(full_viewing_key);
         let incoming_viewing_key = IncomingViewingKey::from(full_viewing_key);
 
-        let ivk_string = incoming_viewing_key.to_string();
-        let incoming_viewing_key_2: IncomingViewingKey = ivk_string.parse().unwrap();
-        prop_assert_eq![incoming_viewing_key, incoming_viewing_key_2];
-
         let _outgoing_viewing_key = OutgoingViewingKey::from(full_viewing_key);
 
         let diversifier = Diversifier::from(diversifier_key);