diff --git a/openpgp-card-sequoia/src/card.rs b/openpgp-card-sequoia/src/card.rs
index cc89f6c..7212b83 100644
--- a/openpgp-card-sequoia/src/card.rs
+++ b/openpgp-card-sequoia/src/card.rs
@@ -4,8 +4,6 @@
 //! Perform operations on a card. Different states of a card are modeled by
 //! different types, such as `Open`, `User`, `Sign`, `Admin`.
 
-use anyhow::{anyhow, Result};
-
 use sequoia_openpgp::cert::amalgamation::key::ValidErasedKeyAmalgamation;
 use sequoia_openpgp::packet::key::SecretParts;
 use sequoia_openpgp::Cert;
@@ -188,7 +186,7 @@ impl<'a> Open<'a> {
         self.ard.historical_bytes()
     }
 
-    pub fn extended_length_information(&self) -> Result<Option<ExtendedLengthInfo>> {
+    pub fn extended_length_information(&self) -> Result<Option<ExtendedLengthInfo>, Error> {
         self.ard.extended_length_information()
     }
 
@@ -206,12 +204,12 @@ impl<'a> Open<'a> {
         self.ard.extended_capabilities()
     }
 
-    pub fn algorithm_attributes(&self, key_type: KeyType) -> Result<Algo> {
+    pub fn algorithm_attributes(&self, key_type: KeyType) -> Result<Algo, Error> {
         self.ard.algorithm_attributes(key_type)
     }
 
     /// PW status Bytes
-    pub fn pw_status_bytes(&self) -> Result<PWStatusBytes> {
+    pub fn pw_status_bytes(&self) -> Result<PWStatusBytes, Error> {
         self.ard.pw_status_bytes()
     }
 
@@ -259,22 +257,22 @@ impl<'a> Open<'a> {
 
     // --- URL (5f50) ---
 
-    pub fn url(&mut self) -> Result<String> {
+    pub fn url(&mut self) -> Result<String, Error> {
         Ok(String::from_utf8_lossy(&self.opt.url()?).to_string())
     }
 
     // --- cardholder related data (65) ---
-    pub fn cardholder_related_data(&mut self) -> Result<CardholderRelatedData> {
+    pub fn cardholder_related_data(&mut self) -> Result<CardholderRelatedData, Error> {
         self.opt.cardholder_related_data()
     }
 
     // --- security support template (7a) ---
-    pub fn security_support_template(&mut self) -> Result<SecuritySupportTemplate> {
+    pub fn security_support_template(&mut self) -> Result<SecuritySupportTemplate, Error> {
         self.opt.security_support_template()
     }
 
     // DO "Algorithm Information" (0xFA)
-    pub fn algorithm_information(&mut self) -> Result<Option<AlgoInfo>> {
+    pub fn algorithm_information(&mut self) -> Result<Option<AlgoInfo>, Error> {
         // The DO "Algorithm Information" (Tag FA) shall be present if
         // Algorithm attributes can be changed
         let ec = self.extended_capabilities()?;
@@ -288,20 +286,20 @@ impl<'a> Open<'a> {
     }
 
     /// Firmware Version, YubiKey specific (?)
-    pub fn firmware_version(&mut self) -> Result<Vec<u8>> {
+    pub fn firmware_version(&mut self) -> Result<Vec<u8>, Error> {
         self.opt.firmware_version()
     }
 
     // ----------
 
-    pub fn public_key(&mut self, key_type: KeyType) -> Result<PublicKeyMaterial> {
+    pub fn public_key(&mut self, key_type: KeyType) -> Result<PublicKeyMaterial, Error> {
         self.opt.public_key(key_type).map_err(|e| e.into())
     }
 
     // ----------
 
     /// Delete all state on this OpenPGP card
-    pub fn factory_reset(&mut self) -> Result<()> {
+    pub fn factory_reset(&mut self) -> Result<(), Error> {
         self.opt.factory_reset()
     }
 }
@@ -354,12 +352,12 @@ impl<'app, 'open> Admin<'app, 'open> {
 impl Admin<'_, '_> {
     pub fn set_name(&mut self, name: &str) -> Result<(), Error> {
         if name.len() >= 40 {
-            return Err(anyhow!("name too long").into());
+            return Err(Error::InternalError("name too long".into()));
         }
 
         // All chars must be in ASCII7
         if name.chars().any(|c| !c.is_ascii()) {
-            return Err(anyhow!("Invalid char in name").into());
+            return Err(Error::InternalError("Invalid char in name".into()));
         };
 
         self.oc.opt.set_name(name.as_bytes())
@@ -367,7 +365,7 @@ impl Admin<'_, '_> {
 
     pub fn set_lang(&mut self, lang: &[Lang]) -> Result<(), Error> {
         if lang.len() > 8 {
-            return Err(anyhow!("lang too long").into());
+            return Err(Error::InternalError("lang too long".into()));
         }
 
         self.oc.opt.set_lang(lang)
@@ -379,7 +377,7 @@ impl Admin<'_, '_> {
 
     pub fn set_url(&mut self, url: &str) -> Result<(), Error> {
         if url.chars().any(|c| !c.is_ascii()) {
-            return Err(anyhow!("Invalid char in url").into());
+            return Err(Error::InternalError("Invalid char in url".into()));
         }
 
         // Check for max len
@@ -393,7 +391,7 @@ impl Admin<'_, '_> {
 
             self.oc.opt.set_url(url.as_bytes())
         } else {
-            Err(anyhow!("URL too long").into())
+            Err(Error::InternalError("URL too long".into()))
         }
     }
 
diff --git a/openpgp-card-sequoia/src/decryptor.rs b/openpgp-card-sequoia/src/decryptor.rs
index ff1a48b..cff5e3b 100644
--- a/openpgp-card-sequoia/src/decryptor.rs
+++ b/openpgp-card-sequoia/src/decryptor.rs
@@ -48,13 +48,13 @@ impl<'a, 'app> CardDecryptor<'a, 'app> {
                 let public = eka.key().clone();
                 Ok(Self { ca, public })
             } else {
-                Err(Error::InternalError(anyhow!(
+                Err(Error::InternalError(format!(
                     "Failed to find (sub)key {} in cert",
                     fp
                 )))
             }
         } else {
-            Err(Error::InternalError(anyhow!(
+            Err(Error::InternalError(format!(
                 "Failed to get the decryption key's Fingerprint from the card"
             )))
         }
diff --git a/openpgp-card-sequoia/src/privkey.rs b/openpgp-card-sequoia/src/privkey.rs
index dc0a1fa..d5dbb0b 100644
--- a/openpgp-card-sequoia/src/privkey.rs
+++ b/openpgp-card-sequoia/src/privkey.rs
@@ -4,7 +4,6 @@
 use std::convert::TryFrom;
 use std::convert::TryInto;
 
-use anyhow::Result;
 use openpgp::cert::amalgamation::key::ValidErasedKeyAmalgamation;
 use openpgp::crypto::{mpi, mpi::ProtectedMPI, mpi::MPI};
 use openpgp::packet::{
@@ -49,14 +48,15 @@ impl SequoiaKey {
 /// Implement the `CardUploadableKey` trait that openpgp-card uses to
 /// upload (sub)keys to a card.
 impl CardUploadableKey for SequoiaKey {
-    fn private_key(&self) -> Result<PrivateKeyMaterial> {
+    fn private_key(&self) -> Result<PrivateKeyMaterial, Error> {
         // Decrypt key with password, if set
         let key = match &self.password {
             None => self.key.clone(),
             Some(pw) => self
                 .key
                 .clone()
-                .decrypt_secret(&openpgp::crypto::Password::from(pw.as_str()))?,
+                .decrypt_secret(&openpgp::crypto::Password::from(pw.as_str()))
+                .map_err(|e| Error::InternalError(format!("sequoia decrypt failed {:?}", e)))?,
         };
 
         // Get private cryptographic material
@@ -124,8 +124,15 @@ struct SqRSA {
 
 impl SqRSA {
     #[allow(clippy::many_single_char_names)]
-    fn new(e: MPI, d: ProtectedMPI, n: MPI, p: ProtectedMPI, q: ProtectedMPI) -> Result<Self> {
-        let nettle = nettle::rsa::PrivateKey::new(d.value(), p.value(), q.value(), None)?;
+    fn new(
+        e: MPI,
+        d: ProtectedMPI,
+        n: MPI,
+        p: ProtectedMPI,
+        q: ProtectedMPI,
+    ) -> Result<Self, Error> {
+        let nettle = nettle::rsa::PrivateKey::new(d.value(), p.value(), q.value(), None)
+            .map_err(|e| Error::InternalError(format!("nettle error {:?}", e)))?;
 
         Ok(Self { e, n, p, q, nettle })
     }
diff --git a/openpgp-card-sequoia/src/signer.rs b/openpgp-card-sequoia/src/signer.rs
index cd0854e..9ff1a27 100644
--- a/openpgp-card-sequoia/src/signer.rs
+++ b/openpgp-card-sequoia/src/signer.rs
@@ -46,13 +46,13 @@ impl<'a, 'app> CardSigner<'a, 'app> {
                 let key = eka.key().clone();
                 Ok(Self::with_pubkey(ca, key))
             } else {
-                Err(Error::InternalError(anyhow!(
+                Err(Error::InternalError(format!(
                     "Failed to find (sub)key {} in cert",
                     fp
                 )))
             }
         } else {
-            Err(Error::InternalError(anyhow!(
+            Err(Error::InternalError(format!(
                 "Failed to get the signing key's Fingerprint from the card"
             )))
         }
diff --git a/openpgp-card-sequoia/src/util.rs b/openpgp-card-sequoia/src/util.rs
index ab0f49a..e31abd3 100644
--- a/openpgp-card-sequoia/src/util.rs
+++ b/openpgp-card-sequoia/src/util.rs
@@ -177,12 +177,14 @@ pub fn public_key_material_to_key(
     pkm: &PublicKeyMaterial,
     key_type: KeyType,
     time: KeyGenerationTime,
-) -> Result<PublicKey> {
+) -> Result<PublicKey, Error> {
     let time = Timestamp::from(time.get()).into();
 
     match pkm {
         PublicKeyMaterial::R(rsa) => {
-            let k4 = Key4::import_public_rsa(rsa.v(), rsa.n(), Some(time))?;
+            let k4 = Key4::import_public_rsa(rsa.v(), rsa.n(), Some(time)).map_err(|e| {
+                Error::InternalError(format!("sequoia Key4::import_public_rsa failed: {:?}", e))
+            })?;
 
             Ok(k4.into())
         }
@@ -202,7 +204,13 @@ pub fn public_key_material_to_key(
                     KeyType::Authentication | KeyType::Signing => {
                         if algo_ecc.curve() == Curve::Ed25519 {
                             // EdDSA
-                            let k4 = Key4::import_public_ed25519(ecc.data(), time)?;
+                            let k4 =
+                                Key4::import_public_ed25519(ecc.data(), time).map_err(|e| {
+                                    Error::InternalError(format!(
+                                        "sequoia Key4::import_public_ed25519 failed: {:?}",
+                                        e
+                                    ))
+                                })?;
 
                             Ok(Key::from(k4))
                         } else {
@@ -214,7 +222,13 @@ pub fn public_key_material_to_key(
                                     curve,
                                     q: mpi::MPI::new(ecc.data()),
                                 },
-                            )?;
+                            )
+                            .map_err(|e| {
+                                Error::InternalError(format!(
+                                    "sequoia Key4::new for ECDSA failed: {:?}",
+                                    e
+                                ))
+                            })?;
 
                             Ok(k4.into())
                         }
@@ -225,7 +239,13 @@ pub fn public_key_material_to_key(
                             // ok when a cert already exists
 
                             // EdDSA
-                            let k4 = Key4::import_public_cv25519(ecc.data(), None, None, time)?;
+                            let k4 = Key4::import_public_cv25519(ecc.data(), None, None, time)
+                                .map_err(|e| {
+                                    Error::InternalError(format!(
+                                        "sequoia Key4::import_public_cv25519 failed: {:?}",
+                                        e
+                                    ))
+                                })?;
 
                             Ok(k4.into())
                         } else {
@@ -242,7 +262,13 @@ pub fn public_key_material_to_key(
                                     hash: Default::default(),
                                     sym: Default::default(),
                                 },
-                            )?;
+                            )
+                            .map_err(|e| {
+                                Error::InternalError(format!(
+                                    "sequoia Key4::new for ECDH failed: {:?}",
+                                    e
+                                ))
+                            })?;
 
                             Ok(k4.into())
                         }
diff --git a/openpgp-card/src/algorithm.rs b/openpgp-card/src/algorithm.rs
index d4355a1..93fc260 100644
--- a/openpgp-card/src/algorithm.rs
+++ b/openpgp-card/src/algorithm.rs
@@ -86,7 +86,7 @@ impl AlgoSimple {
         key_type: KeyType,
         ard: &ApplicationRelatedData,
         algo_info: Option<AlgoInfo>,
-    ) -> Result<Algo> {
+    ) -> Result<Algo, crate::Error> {
         let algo = match self {
             Self::RSA1k => Algo::Rsa(keys::determine_rsa_attrs(1024, key_type, ard, algo_info)?),
             Self::RSA2k => Algo::Rsa(keys::determine_rsa_attrs(2048, key_type, ard, algo_info)?),
@@ -189,7 +189,9 @@ impl Algo {
         match self {
             Algo::Rsa(rsa) => Self::rsa_algo_attrs(rsa),
             Algo::Ecc(ecc) => Self::ecc_algo_attrs(ecc.oid(), ecc.ecc_type()),
-            _ => Err(anyhow!("Unexpected Algo {:?}", self).into()),
+            _ => Err(Error::UnsupportedAlgo(
+                format!("Unexpected Algo {:?}", self).into(),
+            )),
         }
     }
 
@@ -327,7 +329,7 @@ impl Curve {
 }
 
 impl TryFrom<&[u8]> for Curve {
-    type Error = anyhow::Error;
+    type Error = crate::Error;
 
     fn try_from(oid: &[u8]) -> Result<Self, Self::Error> {
         use Curve::*;
@@ -349,7 +351,7 @@ impl TryFrom<&[u8]> for Curve {
             [0x2b, 0x65, 0x71] => Ed448,
             [0x2b, 0x65, 0x6f] => X448,
 
-            _ => return Err(anyhow!("Unknown curve OID {:?}", oid)),
+            _ => return Err(Error::ParseError(format!("Unknown curve OID {:?}", oid))),
         };
 
         Ok(curve)
diff --git a/openpgp-card/src/apdu.rs b/openpgp-card/src/apdu.rs
index 4bb71ab..1d8c3f6 100644
--- a/openpgp-card/src/apdu.rs
+++ b/openpgp-card/src/apdu.rs
@@ -153,9 +153,7 @@ where
             let cla = if last { 0x00 } else { 0x10 };
             let partial = Command::new(cla, cmd.ins(), cmd.p1(), cmd.p2(), d.to_vec());
 
-            let serialized = partial
-                .serialize(ext_len, expect_response)
-                .map_err(Error::InternalError)?;
+            let serialized = partial.serialize(ext_len, expect_response)?;
 
             log::debug!(" -> chained APDU command: {:x?}", &serialized);
 
diff --git a/openpgp-card/src/apdu/command.rs b/openpgp-card/src/apdu/command.rs
index d2ad053..81dc83c 100644
--- a/openpgp-card/src/apdu/command.rs
+++ b/openpgp-card/src/apdu/command.rs
@@ -69,7 +69,11 @@ impl Command {
     /// Serialize a Command (for sending to a card).
     ///
     /// See OpenPGP card spec, chapter 7 (pg 47)
-    pub(crate) fn serialize(&self, ext_len: bool, expect_response: Expect) -> Result<Vec<u8>> {
+    pub(crate) fn serialize(
+        &self,
+        ext_len: bool,
+        expect_response: Expect,
+    ) -> Result<Vec<u8>, crate::Error> {
         // FIXME? (from scd/apdu.c):
         //  T=0 does not allow the use of Lc together with Le;
         //  thus disable Le in this case.
diff --git a/openpgp-card/src/card_do.rs b/openpgp-card/src/card_do.rs
index 7fe633d..d389767 100644
--- a/openpgp-card/src/card_do.rs
+++ b/openpgp-card/src/card_do.rs
@@ -3,7 +3,6 @@
 
 //! OpenPGP card data objects (DO)
 
-use anyhow::{anyhow, Result};
 use chrono::{DateTime, Utc};
 use std::convert::TryFrom;
 use std::convert::TryInto;
@@ -41,7 +40,7 @@ impl ApplicationRelatedData {
         if let Some(aid) = aid {
             Ok(ApplicationIdentifier::try_from(&aid.serialize()[..])?)
         } else {
-            Err(anyhow!("Couldn't get Application ID.").into())
+            Err(Error::NotFound("Couldn't get Application ID.".to_string()))
         }
     }
 
@@ -54,13 +53,15 @@ impl ApplicationRelatedData {
             log::debug!("Historical bytes: {:x?}", hist);
             (hist.serialize().as_slice()).try_into()
         } else {
-            Err(anyhow!("Failed to get historical bytes.").into())
+            Err(Error::NotFound(
+                "Failed to get historical bytes.".to_string(),
+            ))
         }
     }
 
     /// Get extended length information (ISO 7816-4), which
     /// contains maximum number of bytes for command and response.
-    pub fn extended_length_information(&self) -> Result<Option<ExtendedLengthInfo>> {
+    pub fn extended_length_information(&self) -> Result<Option<ExtendedLengthInfo>, Error> {
         // get from cached "application related data"
         let eli = self.0.find(&[0x7f, 0x66].into());
 
@@ -100,27 +101,29 @@ impl ApplicationRelatedData {
                 version,
             ))?)
         } else {
-            Err(anyhow!("Failed to get extended capabilities.").into())
+            Err(Error::NotFound(
+                "Failed to get extended capabilities.".to_string(),
+            ))
         }
     }
 
     /// Get algorithm attributes (for each key type)
-    pub fn algorithm_attributes(&self, key_type: KeyType) -> Result<Algo> {
+    pub fn algorithm_attributes(&self, key_type: KeyType) -> Result<Algo, Error> {
         // get from cached "application related data"
         let aa = self.0.find(&[key_type.algorithm_tag()].into());
 
         if let Some(aa) = aa {
             Algo::try_from(&aa.serialize()[..])
         } else {
-            Err(anyhow!(
+            Err(Error::NotFound(format!(
                 "Failed to get algorithm attributes for {:?}.",
                 key_type
-            ))
+            )))
         }
     }
 
     /// Get PW status Bytes
-    pub fn pw_status_bytes(&self) -> Result<PWStatusBytes> {
+    pub fn pw_status_bytes(&self) -> Result<PWStatusBytes, Error> {
         // get from cached "application related data"
         let psb = self.0.find(&[0xc4].into());
 
@@ -131,7 +134,9 @@ impl ApplicationRelatedData {
 
             Ok(pws)
         } else {
-            Err(anyhow!("Failed to get PW status Bytes."))
+            Err(Error::NotFound(
+                "Failed to get PW status Bytes.".to_string(),
+            ))
         }
     }
 
@@ -148,12 +153,12 @@ impl ApplicationRelatedData {
 
             Ok(fp)
         } else {
-            Err(anyhow!("Failed to get fingerprints.").into())
+            Err(Error::NotFound("Failed to get fingerprints.".into()))
         }
     }
 
     /// Generation dates/times of key pairs
-    pub fn key_generation_times(&self) -> Result<KeySet<KeyGenerationTime>, Error> {
+    pub fn key_generation_times(&self) -> Result<KeySet<KeyGenerationTime>, crate::Error> {
         let kg = self.0.find(&[0xcd].into());
 
         if let Some(kg) = kg {
@@ -163,7 +168,9 @@ impl ApplicationRelatedData {
 
             Ok(kg)
         } else {
-            Err(anyhow!("Failed to get key generation times.").into())
+            Err(Error::NotFound(format!(
+                "Failed to get key generation times."
+            )))
         }
     }
 }
@@ -446,11 +453,14 @@ impl Fingerprint {
 }
 
 /// Helper fn for nom parsing
-pub(crate) fn complete<O>(result: nom::IResult<&[u8], O>) -> Result<O, anyhow::Error> {
-    let (rem, output) = result.map_err(|err| anyhow!("Parsing failed: {:?}", err))?;
+pub(crate) fn complete<O>(result: nom::IResult<&[u8], O>) -> Result<O, Error> {
+    let (rem, output) = result.map_err(|_err| Error::ParseError(format!("Parsing failed")))?;
     if rem.is_empty() {
         Ok(output)
     } else {
-        Err(anyhow!("Parsing incomplete -- trailing data: {:x?}", rem))
+        Err(Error::ParseError(format!(
+            "Parsing incomplete, trailing data: {:x?}",
+            rem
+        )))
     }
 }
diff --git a/openpgp-card/src/card_do/algo_attrs.rs b/openpgp-card/src/card_do/algo_attrs.rs
index 23462f8..d793743 100644
--- a/openpgp-card/src/card_do/algo_attrs.rs
+++ b/openpgp-card/src/card_do/algo_attrs.rs
@@ -141,9 +141,9 @@ pub(crate) fn parse(input: &[u8]) -> nom::IResult<&[u8], Algo> {
 }
 
 impl TryFrom<&[u8]> for Algo {
-    type Error = anyhow::Error;
+    type Error = crate::Error;
 
-    fn try_from(data: &[u8]) -> Result<Self> {
+    fn try_from(data: &[u8]) -> Result<Self, crate::Error> {
         complete(parse(data))
     }
 }
diff --git a/openpgp-card/src/card_do/algo_info.rs b/openpgp-card/src/card_do/algo_info.rs
index 5327060..816687d 100644
--- a/openpgp-card/src/card_do/algo_info.rs
+++ b/openpgp-card/src/card_do/algo_info.rs
@@ -87,9 +87,9 @@ pub(self) fn parse(input: &[u8]) -> nom::IResult<&[u8], Vec<(KeyType, Algo)>> {
 }
 
 impl TryFrom<&[u8]> for AlgoInfo {
-    type Error = anyhow::Error;
+    type Error = crate::Error;
 
-    fn try_from(input: &[u8]) -> Result<Self> {
+    fn try_from(input: &[u8]) -> Result<Self, Self::Error> {
         Ok(AlgoInfo(complete(parse(input))?))
     }
 }
diff --git a/openpgp-card/src/card_do/application_id.rs b/openpgp-card/src/card_do/application_id.rs
index b319751..cab10f1 100644
--- a/openpgp-card/src/card_do/application_id.rs
+++ b/openpgp-card/src/card_do/application_id.rs
@@ -31,9 +31,9 @@ fn parse(input: &[u8]) -> nom::IResult<&[u8], ApplicationIdentifier> {
 }
 
 impl TryFrom<&[u8]> for ApplicationIdentifier {
-    type Error = anyhow::Error;
+    type Error = crate::Error;
 
-    fn try_from(data: &[u8]) -> Result<Self> {
+    fn try_from(data: &[u8]) -> Result<Self, Self::Error> {
         complete(parse(data))
     }
 }
diff --git a/openpgp-card/src/card_do/cardholder.rs b/openpgp-card/src/card_do/cardholder.rs
index 95a5f7a..221e0db 100644
--- a/openpgp-card/src/card_do/cardholder.rs
+++ b/openpgp-card/src/card_do/cardholder.rs
@@ -25,9 +25,9 @@ impl CardholderRelatedData {
 }
 
 impl TryFrom<&[u8]> for CardholderRelatedData {
-    type Error = anyhow::Error;
+    type Error = crate::Error;
 
-    fn try_from(data: &[u8]) -> Result<Self> {
+    fn try_from(data: &[u8]) -> Result<Self, crate::Error> {
         let value = Value::from(data, true)?;
         let tlv = Tlv::new([0x65], value);
 
diff --git a/openpgp-card/src/card_do/extended_cap.rs b/openpgp-card/src/card_do/extended_cap.rs
index b78020d..0e50503 100644
--- a/openpgp-card/src/card_do/extended_cap.rs
+++ b/openpgp-card/src/card_do/extended_cap.rs
@@ -3,7 +3,6 @@
 
 //! 4.4.3.7 Extended Capabilities
 
-use anyhow::{anyhow, Result};
 use std::convert::TryFrom;
 
 use crate::card_do::ExtendedCapabilities;
@@ -80,15 +79,17 @@ impl TryFrom<(&[u8], u16)> for ExtendedCapabilities {
             let i9 = input[9];
 
             if i8 > 1 {
-                return Err(
-                    anyhow!("Illegal value '{}' for pin_block_2_format_support", i8).into(),
-                );
+                return Err(Error::ParseError(
+                    format!("Illegal value '{}' for pin_block_2_format_support", i8).into(),
+                ));
             }
 
             pin_block_2_format_support = Some(i8 != 0);
 
             if i9 > 1 {
-                return Err(anyhow!("Illegal value '{}' for mse_command_support", i9).into());
+                return Err(Error::ParseError(
+                    format!("Illegal value '{}' for mse_command_support", i9).into(),
+                ));
             }
             mse_command_support = Some(i9 != 0);
         }
diff --git a/openpgp-card/src/card_do/extended_length_info.rs b/openpgp-card/src/card_do/extended_length_info.rs
index 9c17b9b..de7f443 100644
--- a/openpgp-card/src/card_do/extended_length_info.rs
+++ b/openpgp-card/src/card_do/extended_length_info.rs
@@ -32,7 +32,7 @@ impl ExtendedLengthInfo {
 }
 
 impl TryFrom<&[u8]> for ExtendedLengthInfo {
-    type Error = anyhow::Error;
+    type Error = crate::Error;
 
     fn try_from(input: &[u8]) -> Result<Self, Self::Error> {
         let eli = complete(parse(input))?;
diff --git a/openpgp-card/src/card_do/fingerprint.rs b/openpgp-card/src/card_do/fingerprint.rs
index f695738..8b546b9 100644
--- a/openpgp-card/src/card_do/fingerprint.rs
+++ b/openpgp-card/src/card_do/fingerprint.rs
@@ -3,7 +3,6 @@
 
 //! Fingerprint for a single key slot
 
-use anyhow::anyhow;
 use nom::{bytes::complete as bytes, combinator, sequence};
 use std::convert::TryFrom;
 use std::convert::TryInto;
@@ -28,7 +27,9 @@ impl TryFrom<&[u8]> for Fingerprint {
             let array: [u8; 20] = input.try_into().unwrap();
             Ok(array.into())
         } else {
-            Err(anyhow!("Unexpected fingerprint length {}", input.len()).into())
+            Err(Error::ParseError(
+                format!("Unexpected fingerprint length {}", input.len()).into(),
+            ))
         }
     }
 }
@@ -88,8 +89,7 @@ impl TryFrom<&[u8]> for KeySet<Fingerprint> {
         // been completely consumed.
         self::fingerprints(input)
             .map(|res| res.1)
-            .map_err(|err| anyhow!("Parsing failed: {:?}", err))
-            .map_err(Error::InternalError)
+            .map_err(|_err| Error::ParseError("Parsing failed".into()))
     }
 }
 
diff --git a/openpgp-card/src/card_do/historical.rs b/openpgp-card/src/card_do/historical.rs
index 7e0daca..969ea42 100644
--- a/openpgp-card/src/card_do/historical.rs
+++ b/openpgp-card/src/card_do/historical.rs
@@ -5,7 +5,6 @@
 
 use crate::card_do::{CardCapabilities, CardServiceData, HistoricalBytes};
 use crate::Error;
-use anyhow::{anyhow, Result};
 use std::convert::TryFrom;
 
 impl CardCapabilities {
@@ -77,7 +76,7 @@ impl HistoricalBytes {
 }
 
 impl TryFrom<&[u8]> for HistoricalBytes {
-    type Error = Error;
+    type Error = crate::Error;
 
     fn try_from(mut data: &[u8]) -> Result<Self, Self::Error> {
         // workaround-hack for "ledger" with zero-padded historical bytes
@@ -95,18 +94,18 @@ impl TryFrom<&[u8]> for HistoricalBytes {
         if len < 4 {
             // historical bytes cannot be this short
 
-            return Err(anyhow!(format!(
-                "Historical bytes too short ({} bytes), must be >= 4",
-                len
-            ))
-            .into());
+            return Err(Error::ParseError(
+                format!("Historical bytes too short ({} bytes), must be >= 4", len).into(),
+            ));
         }
 
         if data[0] != 0 {
             // The OpenPGP application assumes a category indicator byte
             // set to '00' (o-card 3.4.1, pg 44)
 
-            return Err(anyhow!("Unexpected category indicator in historical bytes").into());
+            return Err(Error::ParseError(
+                "Unexpected category indicator in historical bytes".into(),
+            ));
         }
 
         // category indicator byte
@@ -127,14 +126,15 @@ impl TryFrom<&[u8]> for HistoricalBytes {
             // (1 byte for the tl, plus `l` bytes of data for this ctlv)
             // (e.g. len = 4 -> tl + 3byte data)
             if ctlv.len() < (1 + l as usize) {
-                return Err(anyhow!(
-                    "Illegal length value in Historical Bytes TL {} len {} \
-                    l {}",
-                    ctlv[0],
-                    ctlv.len(),
-                    l
-                )
-                .into());
+                return Err(Error::ParseError(
+                    format!(
+                        "Illegal length value in Historical Bytes TL {} len {} l {}",
+                        ctlv[0],
+                        ctlv.len(),
+                        l
+                    )
+                    .into(),
+                ));
             }
 
             match (t, l) {
@@ -177,7 +177,9 @@ impl TryFrom<&[u8]> for HistoricalBytes {
                 5
             }
             _ => {
-                return Err(anyhow!("unexpected status indicator in historical bytes").into());
+                return Err(Error::ParseError(
+                    "unexpected status indicator in historical bytes".into(),
+                ));
             }
         };
 
diff --git a/openpgp-card/src/card_do/key_generation_times.rs b/openpgp-card/src/card_do/key_generation_times.rs
index 09e7005..e990c7a 100644
--- a/openpgp-card/src/card_do/key_generation_times.rs
+++ b/openpgp-card/src/card_do/key_generation_times.rs
@@ -3,12 +3,10 @@
 
 //! Generation date/time of key pair (see spec pg. 24)
 
-use anyhow::anyhow;
-use chrono::{DateTime, NaiveDateTime, Utc};
-use nom::{combinator, number::complete as number, sequence};
-
 use crate::card_do::{KeyGenerationTime, KeySet};
 use crate::Error;
+use chrono::{DateTime, NaiveDateTime, Utc};
+use nom::{combinator, number::complete as number, sequence};
 use std::convert::TryFrom;
 
 impl From<KeyGenerationTime> for DateTime<Utc> {
@@ -69,8 +67,7 @@ impl TryFrom<&[u8]> for KeySet<KeyGenerationTime> {
         // hasn't been completely consumed.
         self::key_generation_set(input)
             .map(|res| res.1)
-            .map_err(|err| anyhow!("Parsing failed: {:?}", err))
-            .map_err(Error::InternalError)
+            .map_err(|_err| Error::ParseError(format!("Parsing failed")))
     }
 }
 
diff --git a/openpgp-card/src/card_do/pw_status.rs b/openpgp-card/src/card_do/pw_status.rs
index c1fa9da..ae16b5d 100644
--- a/openpgp-card/src/card_do/pw_status.rs
+++ b/openpgp-card/src/card_do/pw_status.rs
@@ -3,8 +3,6 @@
 
 //! PW status Bytes (see spec page 23)
 
-use anyhow::anyhow;
-
 use crate::card_do::PWStatusBytes;
 use crate::Error;
 use std::convert::TryFrom;
@@ -41,7 +39,7 @@ impl PWStatusBytes {
 }
 
 impl TryFrom<&[u8]> for PWStatusBytes {
-    type Error = Error;
+    type Error = crate::Error;
 
     fn try_from(input: &[u8]) -> Result<Self, Self::Error> {
         if input.len() == 7 {
@@ -67,7 +65,7 @@ impl TryFrom<&[u8]> for PWStatusBytes {
                 err_count_pw3,
             })
         } else {
-            Err(Error::InternalError(anyhow!(
+            Err(Error::ParseError(format!(
                 "Unexpected length of PW Status Bytes: {}",
                 input.len()
             )))
diff --git a/openpgp-card/src/crypto_data.rs b/openpgp-card/src/crypto_data.rs
index c27c467..587cf0b 100644
--- a/openpgp-card/src/crypto_data.rs
+++ b/openpgp-card/src/crypto_data.rs
@@ -61,7 +61,7 @@ pub enum Cryptogram<'a> {
 /// to an OpenPGP card
 pub trait CardUploadableKey {
     /// private key data
-    fn private_key(&self) -> Result<PrivateKeyMaterial>;
+    fn private_key(&self) -> Result<PrivateKeyMaterial, crate::Error>;
 
     /// timestamp of (sub)key creation
     fn timestamp(&self) -> KeyGenerationTime;
diff --git a/openpgp-card/src/errors.rs b/openpgp-card/src/errors.rs
index 8c92836..7dba3d0 100644
--- a/openpgp-card/src/errors.rs
+++ b/openpgp-card/src/errors.rs
@@ -26,8 +26,18 @@ pub enum Error {
     #[error("Unexpected response length: {0}")]
     ResponseLength(usize),
 
+    #[error("Data not found: {0}")]
+    NotFound(String),
+
+    #[error("Couldn't parse data: {0}")]
+    ParseError(String),
+
+    #[error("Unsupported algorithm: {0}")]
+    UnsupportedAlgo(String),
+
+    // FIXME: placeholder, remove again later?
     #[error("Internal error: {0}")]
-    InternalError(anyhow::Error),
+    InternalError(String),
 }
 
 impl From<StatusBytes> for Error {
@@ -36,12 +46,6 @@ impl From<StatusBytes> for Error {
     }
 }
 
-impl From<anyhow::Error> for Error {
-    fn from(ae: anyhow::Error) -> Self {
-        Error::InternalError(ae)
-    }
-}
-
 /// OpenPGP card "Status Bytes" (ok statuses and errors)
 #[derive(thiserror::Error, Debug, PartialEq, Copy, Clone)]
 #[non_exhaustive]
diff --git a/openpgp-card/src/keys.rs b/openpgp-card/src/keys.rs
index 855369d..686aa53 100644
--- a/openpgp-card/src/keys.rs
+++ b/openpgp-card/src/keys.rs
@@ -3,7 +3,6 @@
 
 //! Generate and import keys
 
-use anyhow::{anyhow, Result};
 use std::convert::TryFrom;
 use std::time::{SystemTime, UNIX_EPOCH};
 
@@ -77,7 +76,7 @@ pub(crate) fn gen_key_with_metadata(
     // Store creation timestamp (unix time format, limited to u32)
     let ts = time
         .duration_since(UNIX_EPOCH)
-        .map_err(|e| Error::InternalError(anyhow!(e)))?
+        .map_err(|e| Error::InternalError(format!("This should never happen {}", e)))?
         .as_secs() as u32;
 
     let ts = ts.into();
@@ -92,7 +91,7 @@ pub(crate) fn gen_key_with_metadata(
 }
 
 /// Transform a public key Tlv from the card into PublicKeyMaterial
-fn tlv_to_pubkey(tlv: &Tlv, algo: &Algo) -> Result<PublicKeyMaterial> {
+fn tlv_to_pubkey(tlv: &Tlv, algo: &Algo) -> Result<PublicKeyMaterial, crate::Error> {
     let n = tlv.find(&[0x81].into());
     let v = tlv.find(&[0x82].into());
 
@@ -111,10 +110,10 @@ fn tlv_to_pubkey(tlv: &Tlv, algo: &Algo) -> Result<PublicKeyMaterial> {
             Ok(PublicKeyMaterial::E(ecc))
         }
 
-        (_, _, _) => Err(anyhow!(
+        (_, _, _) => Err(Error::UnsupportedAlgo(format!(
             "Unexpected public key material from card {:?}",
             tlv
-        )),
+        ))),
     }
 }
 
@@ -229,7 +228,7 @@ pub(crate) fn determine_rsa_attrs(
     key_type: KeyType,
     ard: &ApplicationRelatedData,
     algo_info: Option<AlgoInfo>,
-) -> Result<RsaAttrs> {
+) -> Result<RsaAttrs, crate::Error> {
     // Figure out suitable RSA algorithm parameters:
 
     // Does the card offer a list of algorithms?
@@ -273,13 +272,16 @@ pub(crate) fn determine_ecc_attrs(
     ecc_type: EccType,
     key_type: KeyType,
     algo_info: Option<AlgoInfo>,
-) -> Result<EccAttrs> {
+) -> Result<EccAttrs, crate::Error> {
     // If we have an algo_info, refuse upload if oid is not listed
     if let Some(algo_info) = algo_info {
         let algos = check_card_algo_ecc(algo_info, key_type, oid);
         if algos.is_empty() {
             // If oid is not in algo_info, return error.
-            return Err(anyhow!("Oid {:?} unsupported according to algo_info", oid));
+            return Err(Error::UnsupportedAlgo(format!(
+                "Oid {:?} unsupported according to algo_info",
+                oid
+            )));
         }
 
         // Note: Looking up ecc_type in the card's "Algorithm Information"
@@ -332,7 +334,9 @@ fn card_algo_rsa(algo_info: AlgoInfo, key_type: KeyType, rsa_bits: u16) -> Resul
         Ok((**algo.last().unwrap()).clone())
     } else {
         // RSA with this bit length is not in algo_info
-        return Err(anyhow!("RSA {} unsupported according to algo_info", rsa_bits).into());
+        return Err(Error::UnsupportedAlgo(
+            format!("RSA {} unsupported according to algo_info", rsa_bits).into(),
+        ));
     }
 }
 
@@ -518,7 +522,7 @@ fn control_reference_template(key_type: KeyType) -> Result<Tlv, Error> {
         KeyType::Decryption => 0xB8,
         KeyType::Signing => 0xB6,
         KeyType::Authentication => 0xA4,
-        _ => return Err(Error::InternalError(anyhow!("Unexpected KeyType"))),
+        _ => return Err(Error::InternalError("Unexpected KeyType".to_string())),
     };
     Ok(Tlv::new([tag], Value::S(vec![])))
 }
diff --git a/openpgp-card/src/lib.rs b/openpgp-card/src/lib.rs
index d9cbc09..71806f0 100644
--- a/openpgp-card/src/lib.rs
+++ b/openpgp-card/src/lib.rs
@@ -94,10 +94,10 @@ pub trait CardTransaction {
     fn feature_pinpad_modify(&self) -> bool;
 
     /// Verify the PIN `id` via the reader pinpad
-    fn pinpad_verify(&mut self, id: u8) -> Result<Vec<u8>>;
+    fn pinpad_verify(&mut self, pin: PinType) -> Result<Vec<u8>, Error>;
 
     /// Modify the PIN `id` via the reader pinpad
-    fn pinpad_modify(&mut self, id: u8) -> Result<Vec<u8>>;
+    fn pinpad_modify(&mut self, pin: PinType) -> Result<Vec<u8>, Error>;
 
     /// Select the OpenPGP card application
     fn select(&mut self) -> Result<Vec<u8>, Error> {
@@ -110,7 +110,7 @@ pub trait CardTransaction {
     /// (This data should probably be cached in a higher layer. Some parts of
     /// it are needed regularly, and it does not usually change during
     /// normal use of a card.)
-    fn application_related_data(&mut self) -> Result<ApplicationRelatedData> {
+    fn application_related_data(&mut self) -> Result<ApplicationRelatedData, Error> {
         let ad = commands::application_related_data();
         let resp = apdu::send_command(self, ad, true)?;
         let value = Value::from(resp.data()?, true)?;
@@ -128,7 +128,7 @@ pub trait CardTransaction {
     /// This fn initializes the CardCaps by requesting
     /// application_related_data from the card, and setting the
     /// capabilities accordingly.
-    fn initialize(&mut self) -> Result<()> {
+    fn initialize(&mut self) -> Result<(), Error> {
         let ard = self.application_related_data()?;
 
         // Determine chaining/extended length support from card
@@ -242,6 +242,23 @@ impl CardCaps {
     }
 }
 
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub enum PinType {
+    Sign,
+    User,
+    Admin,
+}
+
+impl PinType {
+    pub fn id(&self) -> u8 {
+        match self {
+            PinType::Sign => 0x81,
+            PinType::User => 0x82,
+            PinType::Admin => 0x83,
+        }
+    }
+}
+
 /// Identify a Key slot on an OpenPGP card
 #[derive(Debug, Clone, Copy, Eq, PartialEq)]
 #[non_exhaustive]
diff --git a/openpgp-card/src/openpgp.rs b/openpgp-card/src/openpgp.rs
index 188350a..6a88bf3 100644
--- a/openpgp-card/src/openpgp.rs
+++ b/openpgp-card/src/openpgp.rs
@@ -1,7 +1,6 @@
 // SPDX-FileCopyrightText: 2021-2022 Heiko Schaefer <heiko@schaefer.name>
 // SPDX-License-Identifier: MIT OR Apache-2.0
 
-use anyhow::{anyhow, Result};
 use std::convert::{TryFrom, TryInto};
 
 use crate::algorithm::{Algo, AlgoInfo, AlgoSimple};
@@ -14,7 +13,7 @@ use crate::card_do::{
 use crate::crypto_data::{CardUploadableKey, Cryptogram, Hash, PublicKeyMaterial};
 use crate::tlv::{value::Value, Tlv};
 use crate::{
-    apdu, keys, CardBackend, CardTransaction, Error, KeyType, SmartcardError, StatusBytes,
+    apdu, keys, CardBackend, CardTransaction, Error, KeyType, PinType, SmartcardError, StatusBytes,
 };
 
 /// An OpenPGP card access object, backed by a CardBackend implementation.
@@ -80,7 +79,7 @@ impl<'a> OpenPgpTransaction<'a> {
     /// (This data should probably be cached in a higher layer. Some parts of
     /// it are needed regularly, and it does not usually change during
     /// normal use of a card.)
-    pub fn application_related_data(&mut self) -> Result<ApplicationRelatedData> {
+    pub fn application_related_data(&mut self) -> Result<ApplicationRelatedData, Error> {
         self.tx.application_related_data()
     }
 
@@ -117,14 +116,14 @@ impl<'a> OpenPgpTransaction<'a> {
     // --- login data (5e) ---
 
     /// Get URL (5f50)
-    pub fn url(&mut self) -> Result<Vec<u8>> {
+    pub fn url(&mut self) -> Result<Vec<u8>, Error> {
         let resp = apdu::send_command(self.tx(), commands::url(), true)?;
 
         Ok(resp.data()?.to_vec())
     }
 
     /// Get cardholder related data (65)
-    pub fn cardholder_related_data(&mut self) -> Result<CardholderRelatedData> {
+    pub fn cardholder_related_data(&mut self) -> Result<CardholderRelatedData, Error> {
         let crd = commands::cardholder_related_data();
         let resp = apdu::send_command(self.tx(), crd, true)?;
         resp.check_ok()?;
@@ -133,15 +132,15 @@ impl<'a> OpenPgpTransaction<'a> {
     }
 
     /// Get security support template (7a)
-    pub fn security_support_template(&mut self) -> Result<SecuritySupportTemplate> {
+    pub fn security_support_template(&mut self) -> Result<SecuritySupportTemplate, Error> {
         let sst = commands::security_support_template();
         let resp = apdu::send_command(self.tx(), sst, true)?;
         resp.check_ok()?;
 
         let tlv = Tlv::try_from(resp.data()?)?;
-        let res = tlv
-            .find(&[0x93].into())
-            .ok_or_else(|| anyhow!("Couldn't get SecuritySupportTemplate DO"))?;
+        let res = tlv.find(&[0x93].into()).ok_or_else(|| {
+            Error::NotFound("Couldn't get SecuritySupportTemplate DO".to_string())
+        })?;
 
         if let Value::S(data) = res {
             let mut data = data.to_vec();
@@ -153,7 +152,9 @@ impl<'a> OpenPgpTransaction<'a> {
             let dsc: u32 = u32::from_be_bytes(data);
             Ok(SecuritySupportTemplate { dsc })
         } else {
-            Err(anyhow!("Failed to process SecuritySupportTemplate"))
+            Err(Error::NotFound(
+                "Failed to process SecuritySupportTemplate".to_string(),
+            ))
         }
     }
 
@@ -168,7 +169,7 @@ impl<'a> OpenPgpTransaction<'a> {
     }
 
     /// Get "Algorithm Information"
-    pub fn algorithm_information(&mut self) -> Result<Option<AlgoInfo>> {
+    pub fn algorithm_information(&mut self) -> Result<Option<AlgoInfo>, Error> {
         let resp = apdu::send_command(self.tx(), commands::algo_info(), true)?;
         resp.check_ok()?;
 
@@ -177,7 +178,7 @@ impl<'a> OpenPgpTransaction<'a> {
     }
 
     /// Firmware Version (YubiKey specific (?))
-    pub fn firmware_version(&mut self) -> Result<Vec<u8>> {
+    pub fn firmware_version(&mut self) -> Result<Vec<u8>, Error> {
         let resp = apdu::send_command(self.tx(), commands::firmware_version(), true)?;
 
         Ok(resp.data()?.into())
@@ -187,7 +188,7 @@ impl<'a> OpenPgpTransaction<'a> {
     /// [see:
     /// <https://docs.nitrokey.com/start/linux/multiple-identities.html>
     /// <https://github.com/Nitrokey/nitrokey-start-firmware/pull/33/>]
-    pub fn set_identity(&mut self, id: u8) -> Result<Vec<u8>> {
+    pub fn set_identity(&mut self, id: u8) -> Result<Vec<u8>, Error> {
         let resp = apdu::send_command(self.tx(), commands::set_identity(id), false);
 
         // Apparently it's normal to get "NotTransacted" from pcsclite when
@@ -218,7 +219,7 @@ impl<'a> OpenPgpTransaction<'a> {
     /// Get data from "private use" DO.
     ///
     /// `num` must be between 1 and 4.
-    pub fn private_use_do(&mut self, num: u8) -> Result<Vec<u8>> {
+    pub fn private_use_do(&mut self, num: u8) -> Result<Vec<u8>, Error> {
         assert!((1..=4).contains(&num));
 
         let cmd = commands::private_use_do(num);
@@ -234,7 +235,7 @@ impl<'a> OpenPgpTransaction<'a> {
     /// Access condition:
     /// - 1/3 need PW1 (82)
     /// - 2/4 need PW3
-    pub fn set_private_use_do(&mut self, num: u8, data: Vec<u8>) -> Result<Vec<u8>> {
+    pub fn set_private_use_do(&mut self, num: u8, data: Vec<u8>) -> Result<Vec<u8>, Error> {
         assert!((1..=4).contains(&num));
 
         let cmd = commands::put_private_use_do(num, data);
@@ -260,7 +261,7 @@ impl<'a> OpenPgpTransaction<'a> {
     /// (However, e.g. vanilla Gnuk doesn't support this functionality.
     /// Gnuk needs to be built with the `--enable-factory-reset`
     /// option to the `configure` script to enable this functionality).
-    pub fn factory_reset(&mut self) -> Result<()> {
+    pub fn factory_reset(&mut self) -> Result<(), Error> {
         // send 4 bad requests to verify pw1
         // [apdu 00 20 00 81 08 40 40 40 40 40 40 40 40]
         for _ in 0..4 {
@@ -270,7 +271,9 @@ impl<'a> OpenPgpTransaction<'a> {
                 || resp.status() == StatusBytes::AuthenticationMethodBlocked
                 || matches!(resp.status(), StatusBytes::PasswordNotChecked(_)))
             {
-                return Err(anyhow!("Unexpected status for reset, at pw1."));
+                return Err(Error::InternalError(
+                    "Unexpected status for reset, at pw1.".into(),
+                ));
             }
         }
 
@@ -284,7 +287,9 @@ impl<'a> OpenPgpTransaction<'a> {
                 || resp.status() == StatusBytes::AuthenticationMethodBlocked
                 || matches!(resp.status(), StatusBytes::PasswordNotChecked(_)))
             {
-                return Err(anyhow!("Unexpected status for reset, at pw3."));
+                return Err(Error::InternalError(
+                    "Unexpected status for reset, at pw3.".into(),
+                ));
             }
         }
 
@@ -321,7 +326,7 @@ impl<'a> OpenPgpTransaction<'a> {
     /// access condition is only valid for one PSO:CDS command or remains
     /// valid for several attempts.
     pub fn verify_pw1_for_signing_pinpad(&mut self) -> Result<(), Error> {
-        let res = self.tx().pinpad_verify(0x81)?;
+        let res = self.tx().pinpad_verify(PinType::Sign)?;
         RawResponse::try_from(res)?.try_into()
     }
 
@@ -350,7 +355,7 @@ impl<'a> OpenPgpTransaction<'a> {
     /// an error is returned.
 
     pub fn verify_pw1_pinpad(&mut self) -> Result<(), Error> {
-        let res = self.tx().pinpad_verify(0x82)?;
+        let res = self.tx().pinpad_verify(PinType::User)?;
         RawResponse::try_from(res)?.try_into()
     }
 
@@ -377,7 +382,7 @@ impl<'a> OpenPgpTransaction<'a> {
     /// Verify PW3 (admin) using a pinpad on the card reader. If no usable
     /// pinpad is found, an error is returned.
     pub fn verify_pw3_pinpad(&mut self) -> Result<(), Error> {
-        let res = self.tx().pinpad_verify(0x83)?;
+        let res = self.tx().pinpad_verify(PinType::Admin)?;
         RawResponse::try_from(res)?.try_into()
     }
 
@@ -406,10 +411,12 @@ impl<'a> OpenPgpTransaction<'a> {
         apdu::send_command(self.tx(), change, false)?.try_into()
     }
 
-    /// Change the value of PW1 (user password)  using a pinpad on the
+    /// Change the value of PW1 (0x81) using a pinpad on the
     /// card reader. If no usable pinpad is found, an error is returned.
     pub fn change_pw1_pinpad(&mut self) -> Result<(), Error> {
-        let res = self.tx().pinpad_modify(0x81)?;
+        // Note: for change PW, only 0x81 and 0x83 are used!
+        // 0x82 is implicitly the same as 0x81.
+        let res = self.tx().pinpad_modify(PinType::Sign)?;
         RawResponse::try_from(res)?.try_into()
     }
 
@@ -428,7 +435,7 @@ impl<'a> OpenPgpTransaction<'a> {
     /// Change the value of PW3 (admin password) using a pinpad on the
     /// card reader. If no usable pinpad is found, an error is returned.
     pub fn change_pw3_pinpad(&mut self) -> Result<(), Error> {
-        let res = self.tx().pinpad_modify(0x83)?;
+        let res = self.tx().pinpad_modify(PinType::Admin)?;
         RawResponse::try_from(res)?.try_into()
     }
 
diff --git a/openpgp-card/src/tlv.rs b/openpgp-card/src/tlv.rs
index 4053a61..3df3915 100644
--- a/openpgp-card/src/tlv.rs
+++ b/openpgp-card/src/tlv.rs
@@ -72,7 +72,7 @@ impl Tlv {
 }
 
 impl TryFrom<&[u8]> for Tlv {
-    type Error = anyhow::Error;
+    type Error = crate::Error;
 
     fn try_from(input: &[u8]) -> Result<Self, Self::Error> {
         complete(Tlv::parse(input))
diff --git a/openpgp-card/src/tlv/value.rs b/openpgp-card/src/tlv/value.rs
index efff1a7..fe49c5f 100644
--- a/openpgp-card/src/tlv/value.rs
+++ b/openpgp-card/src/tlv/value.rs
@@ -37,7 +37,7 @@ impl Value {
         }
     }
 
-    pub fn from(data: &[u8], constructed: bool) -> Result<Self> {
+    pub fn from(data: &[u8], constructed: bool) -> Result<Self, crate::Error> {
         complete(Self::parse(data, constructed))
     }
 
diff --git a/pcsc/src/lib.rs b/pcsc/src/lib.rs
index 3be3c0d..6389a06 100644
--- a/pcsc/src/lib.rs
+++ b/pcsc/src/lib.rs
@@ -5,13 +5,12 @@
 //! `openpgp-card`. It uses the PCSC middleware to access the OpenPGP
 //! application on smart cards.
 
-use anyhow::{anyhow, Result};
 use iso7816_tlv::simple::Tlv;
 use std::collections::HashMap;
 use std::convert::TryInto;
 
 use openpgp_card::card_do::ApplicationRelatedData;
-use openpgp_card::{CardBackend, CardCaps, CardTransaction, Error, SmartcardError};
+use openpgp_card::{CardBackend, CardCaps, CardTransaction, Error, PinType, SmartcardError};
 
 const FEATURE_VERIFY_PIN_DIRECT: u8 = 0x06;
 const FEATURE_MODIFY_PIN_DIRECT: u8 = 0x07;
@@ -181,23 +180,21 @@ impl<'b> PcscTransaction<'b> {
     }
 
     /// Get the minimum pin length for pin_id.
-    fn min_pin_len(&self, pin_id: u8) -> Result<u8> {
-        match pin_id {
-            0x81 | 0x82 => Ok(6),
-            0x83 => Ok(8),
-            _ => Err(anyhow!("Unexpected pin_id {}", pin_id)),
+    fn min_pin_len(&self, pin: PinType) -> u8 {
+        match pin {
+            PinType::User | PinType::Sign => 6,
+            PinType::Admin => 8,
         }
     }
     /// Get the maximum pin length for pin_id.
-    fn max_pin_len(&self, pin_id: u8) -> Result<u8> {
+    fn max_pin_len(&self, pin: PinType) -> Result<u8, Error> {
         if let Some(card_caps) = self.card_caps {
-            match pin_id {
-                0x81 | 0x82 => Ok(card_caps.pw1_max_len()),
-                0x83 => Ok(card_caps.pw3_max_len()),
-                _ => Err(anyhow!("Unexpected pin_id {}", pin_id)),
+            match pin {
+                PinType::User | PinType::Sign => Ok(card_caps.pw1_max_len()),
+                PinType::Admin => Ok(card_caps.pw3_max_len()),
             }
         } else {
-            Err(anyhow!("card_caps is None"))
+            Err(Error::InternalError("card_caps is None".into()))
         }
     }
 }
@@ -235,9 +232,9 @@ impl CardTransaction for PcscTransaction<'_> {
         self.reader_caps.contains_key(&FEATURE_MODIFY_PIN_DIRECT)
     }
 
-    fn pinpad_verify(&mut self, pin_id: u8) -> Result<Vec<u8>> {
-        let pin_min_size = self.min_pin_len(pin_id)?;
-        let pin_max_size = self.max_pin_len(pin_id)?;
+    fn pinpad_verify(&mut self, pin: PinType) -> Result<Vec<u8>, Error> {
+        let pin_min_size = self.min_pin_len(pin);
+        let pin_max_size = self.max_pin_len(pin)?;
 
         // Default to varlen, for now.
         // (NOTE: Some readers don't support varlen, and need explicit length
@@ -249,7 +246,7 @@ impl CardTransaction for PcscTransaction<'_> {
             0x00,     /* CLA */
             0x20,     /* INS: VERIFY */
             0x00,     /* P1 */
-            pin_id,   /* P2 */
+            pin.id(), /* P2 */
             fixedlen, /* Lc: 'fixedlen' data bytes */
         ];
         ab_data.extend([0xff].repeat(fixedlen as usize));
@@ -311,22 +308,26 @@ impl CardTransaction for PcscTransaction<'_> {
         let verify_ioctl: [u8; 4] = self
             .reader_caps
             .get(&FEATURE_VERIFY_PIN_DIRECT)
-            .ok_or_else(|| anyhow!("no reader_capability"))?
+            .ok_or_else(|| Error::Smartcard(SmartcardError::Error("no reader_capability".into())))?
             .value()
-            .try_into()?;
+            .try_into()
+            .map_err(|e| Error::ParseError(format!("unexpected feature data: {:?}", e)))?;
 
         let res = self
             .tx
-            .control(u32::from_be_bytes(verify_ioctl).into(), &send, &mut recv)?;
+            .control(u32::from_be_bytes(verify_ioctl).into(), &send, &mut recv)
+            .map_err(|e: pcsc::Error| {
+                Error::Smartcard(SmartcardError::Error(format!("pcsc Error: {:?}", e)))
+            })?;
 
         log::debug!(" <- pcsc pinpad_verify result: {:x?}", res);
 
         Ok(res.to_vec())
     }
 
-    fn pinpad_modify(&mut self, pin_id: u8) -> Result<Vec<u8>> {
-        let pin_min_size = self.min_pin_len(pin_id)?;
-        let pin_max_size = self.max_pin_len(pin_id)?;
+    fn pinpad_modify(&mut self, pin: PinType) -> Result<Vec<u8>, Error> {
+        let pin_min_size = self.min_pin_len(pin);
+        let pin_max_size = self.max_pin_len(pin)?;
 
         // Default to varlen, for now.
         // (NOTE: Some readers don't support varlen, and need explicit length
@@ -338,7 +339,7 @@ impl CardTransaction for PcscTransaction<'_> {
             0x00,         /* CLA */
             0x24,         /* INS: CHANGE_REFERENCE_DATA */
             0x00,         /* P1 */
-            pin_id,       /* P2 */
+            pin.id(),     /* P2 */
             fixedlen * 2, /* Lc: 'fixedlen' data bytes */
         ];
         ab_data.extend([0xff].repeat(fixedlen as usize * 2));
@@ -410,13 +411,17 @@ impl CardTransaction for PcscTransaction<'_> {
         let modify_ioctl: [u8; 4] = self
             .reader_caps
             .get(&FEATURE_MODIFY_PIN_DIRECT)
-            .ok_or_else(|| anyhow!("no reader_capability"))?
+            .ok_or_else(|| Error::Smartcard(SmartcardError::Error("no reader_capability".into())))?
             .value()
-            .try_into()?;
+            .try_into()
+            .map_err(|e| Error::ParseError(format!("unexpected feature data: {:?}", e)))?;
 
         let res = self
             .tx
-            .control(u32::from_be_bytes(modify_ioctl).into(), &send, &mut recv)?;
+            .control(u32::from_be_bytes(modify_ioctl).into(), &send, &mut recv)
+            .map_err(|e: pcsc::Error| {
+                Error::Smartcard(SmartcardError::Error(format!("pcsc Error: {:?}", e)))
+            })?;
 
         log::debug!(" <- pcsc pinpad_modify result: {:x?}", res);
 
@@ -602,7 +607,7 @@ impl PcscBackend {
     /// Initialized a PcscCard:
     /// - Obtain and store feature lists from reader (pinpad functionality).
     /// - Get ARD from card, set CardCaps based on ARD.
-    fn initialize_card(mut self) -> Result<Self> {
+    fn initialize_card(mut self) -> Result<Self, Error> {
         log::debug!("pcsc initialize_card");
 
         let mut h: HashMap<u8, Tlv> = HashMap::default();
diff --git a/scdc/src/lib.rs b/scdc/src/lib.rs
index 260c3c9..4686c2d 100644
--- a/scdc/src/lib.rs
+++ b/scdc/src/lib.rs
@@ -5,7 +5,6 @@
 //! `openpgp-card` crate.
 //! It uses GnuPG's scdaemon (via GnuPG Agent) to access OpenPGP cards.
 
-use anyhow::{anyhow, Result};
 use futures::StreamExt;
 use lazy_static::lazy_static;
 use sequoia_ipc::assuan::Response;
@@ -13,7 +12,7 @@ use sequoia_ipc::gnupg::{Agent, Context};
 use std::sync::Mutex;
 use tokio::runtime::Runtime;
 
-use openpgp_card::{CardBackend, CardCaps, CardTransaction, Error};
+use openpgp_card::{CardBackend, CardCaps, CardTransaction, Error, PinType, SmartcardError};
 
 lazy_static! {
     static ref RT: Mutex<Runtime> = Mutex::new(tokio::runtime::Runtime::new().unwrap());
@@ -82,7 +81,7 @@ impl ScdBackend {
 
     /// Helper fn that shuts down scdaemon via GnuPG Agent.
     /// This may be useful to obtain access to a Smard card via PCSC.
-    pub fn shutdown_scd(agent: Option<Agent>) -> Result<()> {
+    pub fn shutdown_scd(agent: Option<Agent>) -> Result<(), Error> {
         let mut scdc = Self::new(agent, false)?;
 
         scdc.send("SCD RESTART")?;
@@ -96,13 +95,23 @@ impl ScdBackend {
     ///
     /// If `agent` is None, a Context with the default GnuPG home directory
     /// is used.
-    fn new(agent: Option<Agent>, init: bool) -> Result<Self> {
+    fn new(agent: Option<Agent>, init: bool) -> Result<Self, Error> {
         let agent = if let Some(agent) = agent {
             agent
         } else {
             // Create and use a new Agent based on a default Context
-            let ctx = Context::new()?;
-            RT.lock().unwrap().block_on(Agent::connect(&ctx))?
+            let ctx = Context::new().map_err(|e| {
+                Error::Smartcard(SmartcardError::Error(format!("Context::new failed {}", e)))
+            })?;
+            RT.lock()
+                .unwrap()
+                .block_on(Agent::connect(&ctx))
+                .map_err(|e| {
+                    Error::Smartcard(SmartcardError::Error(format!(
+                        "Agent::connect failed {}",
+                        e
+                    )))
+                })?
         };
 
         let mut scdc = Self {
@@ -117,13 +126,22 @@ impl ScdBackend {
         Ok(scdc)
     }
 
+    fn send2(&mut self, cmd: &str) -> Result<(), Error> {
+        self.agent.send(cmd).map_err(|e| {
+            Error::Smartcard(SmartcardError::Error(format!(
+                "scdc agent send failed: {}",
+                e
+            )))
+        })
+    }
+
     /// Call "SCD SERIALNO", which causes scdaemon to be started by gpg
     /// agent (if it's not running yet).
-    fn serialno(&mut self) -> Result<()> {
+    fn serialno(&mut self) -> Result<(), Error> {
         let mut rt = RT.lock().unwrap();
 
         let send = "SCD SERIALNO";
-        self.agent.send(send)?;
+        self.send2(send)?;
 
         while let Some(response) = rt.block_on(self.agent.next()) {
             log::debug!("init res: {:x?}", response);
@@ -138,14 +156,16 @@ impl ScdBackend {
             }
         }
 
-        Err(anyhow!("SCDC init() failed"))
+        Err(Error::Smartcard(SmartcardError::Error(
+            "SCDC init() failed".into(),
+        )))
     }
 
     /// Ask scdameon to switch to using a specific OpenPGP card, based on
     /// its `serial`.
-    fn select_card(&mut self, serial: &str) -> Result<()> {
+    fn select_card(&mut self, serial: &str) -> Result<(), Error> {
         let send = format!("SCD SERIALNO --demand={}", serial);
-        self.agent.send(send)?;
+        self.send2(&send)?;
 
         let mut rt = RT.lock().unwrap();
 
@@ -153,7 +173,9 @@ impl ScdBackend {
             log::debug!("select res: {:x?}", response);
 
             if response.is_err() {
-                return Err(anyhow!("Card not found"));
+                return Err(Error::Smartcard(SmartcardError::CardNotFound(
+                    serial.into(),
+                )));
             }
 
             if let Ok(Response::Status { .. }) = response {
@@ -166,11 +188,13 @@ impl ScdBackend {
             }
         }
 
-        Err(anyhow!("Card not found"))
+        Err(Error::Smartcard(SmartcardError::CardNotFound(
+            serial.into(),
+        )))
     }
 
-    fn send(&mut self, cmd: &str) -> Result<()> {
-        self.agent.send(cmd)?;
+    fn send(&mut self, cmd: &str) -> Result<(), Error> {
+        self.send2(cmd)?;
 
         let mut rt = RT.lock().unwrap();
 
@@ -178,7 +202,7 @@ impl ScdBackend {
             log::debug!("select res: {:x?}", response);
 
             if let Err(e) = response {
-                return Err(anyhow!("Err {:?}", e));
+                return Err(Error::Smartcard(SmartcardError::Error(format!("{:?}", e))));
             }
 
             if let Ok(..) = response {
@@ -191,7 +215,10 @@ impl ScdBackend {
             }
         }
 
-        Err(anyhow!("Error sending command {}", cmd))
+        Err(Error::Smartcard(SmartcardError::Error(format!(
+            "Error sending command {}",
+            cmd
+        ))))
     }
 }
 
@@ -225,23 +252,23 @@ impl CardTransaction for ScdTransaction<'_> {
         log::debug!("SCDC command: '{}'", send);
 
         if send.len() > ASSUAN_LINELENGTH {
-            return Err(Error::InternalError(anyhow!(
+            return Err(Error::Smartcard(SmartcardError::Error(format!(
                 "APDU command is too long ({}) to send via Assuan",
                 send.len()
-            )));
+            ))));
         }
 
-        self.scd.agent.send(send)?;
+        self.scd.send2(&send)?;
 
         let mut rt = RT.lock().unwrap();
 
         while let Some(response) = rt.block_on(self.scd.agent.next()) {
             log::debug!("res: {:x?}", response);
             if response.is_err() {
-                return Err(Error::InternalError(anyhow!(
+                return Err(Error::Smartcard(SmartcardError::Error(format!(
                     "Unexpected error response from SCD {:?}",
                     response
-                )));
+                ))));
             }
 
             if let Ok(Response::Data { partial }) = response {
@@ -256,7 +283,9 @@ impl CardTransaction for ScdTransaction<'_> {
             }
         }
 
-        Err(Error::InternalError(anyhow!("no response found")))
+        Err(Error::Smartcard(SmartcardError::Error(
+            "no response found".into(),
+        )))
     }
 
     fn init_card_caps(&mut self, caps: CardCaps) {
@@ -284,12 +313,12 @@ impl CardTransaction for ScdTransaction<'_> {
     }
 
     /// FIXME: not implemented yet
-    fn pinpad_verify(&mut self, _id: u8) -> Result<Vec<u8>> {
+    fn pinpad_verify(&mut self, _id: PinType) -> Result<Vec<u8>, Error> {
         unimplemented!()
     }
 
     /// FIXME: not implemented yet
-    fn pinpad_modify(&mut self, _id: u8) -> Result<Vec<u8>> {
+    fn pinpad_modify(&mut self, _id: PinType) -> Result<Vec<u8>, Error> {
         unimplemented!()
     }
 }
diff --git a/tools/src/bin/opgpcard/main.rs b/tools/src/bin/opgpcard/main.rs
index 0912e2a..e9a5af2 100644
--- a/tools/src/bin/opgpcard/main.rs
+++ b/tools/src/bin/opgpcard/main.rs
@@ -372,7 +372,7 @@ fn factory_reset(ident: &str) -> Result<()> {
     let mut pgp = OpenPgp::new(&mut card);
 
     let mut open = Open::new(pgp.transaction()?)?;
-    open.factory_reset()
+    open.factory_reset().map_err(|e| anyhow!(e))
 }
 
 fn key_import_yolo(mut admin: Admin, key: &Cert) -> Result<()> {