diff --git a/sdk/src/types/block/address/account.rs b/sdk/src/types/block/address/account.rs
index 9961c53b1f..91483b2980 100644
--- a/sdk/src/types/block/address/account.rs
+++ b/sdk/src/types/block/address/account.rs
@@ -58,8 +58,6 @@ impl core::fmt::Debug for AccountAddress {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/address/ed25519.rs b/sdk/src/types/block/address/ed25519.rs
index f4877b10ad..14cfbeab38 100644
--- a/sdk/src/types/block/address/ed25519.rs
+++ b/sdk/src/types/block/address/ed25519.rs
@@ -47,8 +47,6 @@ impl core::fmt::Debug for Ed25519Address {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/address/nft.rs b/sdk/src/types/block/address/nft.rs
index ddbc06b030..959d21018c 100644
--- a/sdk/src/types/block/address/nft.rs
+++ b/sdk/src/types/block/address/nft.rs
@@ -58,8 +58,6 @@ impl core::fmt::Debug for NftAddress {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/context_input/block_issuance_credit.rs b/sdk/src/types/block/context_input/block_issuance_credit.rs
index 3a1b0fcec5..4105f64ea9 100644
--- a/sdk/src/types/block/context_input/block_issuance_credit.rs
+++ b/sdk/src/types/block/context_input/block_issuance_credit.rs
@@ -26,8 +26,6 @@ impl BlockIssuanceCreditContextInput {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/context_input/commitment.rs b/sdk/src/types/block/context_input/commitment.rs
index 2e00488779..b43be8c69c 100644
--- a/sdk/src/types/block/context_input/commitment.rs
+++ b/sdk/src/types/block/context_input/commitment.rs
@@ -25,8 +25,6 @@ impl CommitmentContextInput {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/context_input/reward.rs b/sdk/src/types/block/context_input/reward.rs
index 3c01197ef4..c49e757483 100644
--- a/sdk/src/types/block/context_input/reward.rs
+++ b/sdk/src/types/block/context_input/reward.rs
@@ -23,8 +23,6 @@ impl RewardContextInput {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/error.rs b/sdk/src/types/block/error.rs
index 3e51800325..5a201ff7ac 100644
--- a/sdk/src/types/block/error.rs
+++ b/sdk/src/types/block/error.rs
@@ -9,7 +9,7 @@ use crypto::Error as CryptoError;
 use prefix_hex::Error as HexError;
 use primitive_types::U256;
 
-use super::{mana::AllotmentCount, protocol::ProtocolParametersHash};
+use super::{mana::AllotmentCount, protocol::ProtocolParametersHash, public_key::PublicKeyCount};
 use crate::types::block::{
     input::UtxoInput,
     output::{
@@ -94,6 +94,7 @@ pub enum Error {
         expected: ProtocolParametersHash,
         actual: ProtocolParametersHash,
     },
+    InvalidPublicKeyCount(<PublicKeyCount as TryFrom<usize>>::Error),
     InvalidReferenceIndex(<UnlockIndex as TryFrom<u16>>::Error),
     InvalidSignature,
     InvalidSignatureKind(u8),
@@ -132,6 +133,7 @@ pub enum Error {
         expected: u8,
         actual: u8,
     },
+    PublicKeysNotUniqueSorted,
     RemainingBytesAfterBlock,
     SelfControlledAccountOutput(AccountId),
     SelfDepositNft(NftId),
@@ -249,6 +251,7 @@ impl fmt::Display for Error {
                     "invalid protocol parameters hash: expected {expected} but got {actual}"
                 )
             }
+            Self::InvalidPublicKeyCount(count) => write!(f, "invalid public key count: {count}"),
             Self::InvalidReferenceIndex(index) => write!(f, "invalid reference index: {index}"),
             Self::InvalidSignature => write!(f, "invalid signature provided"),
             Self::InvalidSignatureKind(k) => write!(f, "invalid signature kind: {k}"),
@@ -308,6 +311,7 @@ impl fmt::Display for Error {
             Self::ProtocolVersionMismatch { expected, actual } => {
                 write!(f, "protocol version mismatch: expected {expected} but got {actual}")
             }
+            Self::PublicKeysNotUniqueSorted => write!(f, "public keys are not unique and/or sorted"),
             Self::RemainingBytesAfterBlock => {
                 write!(f, "remaining bytes after block")
             }
diff --git a/sdk/src/types/block/input/utxo.rs b/sdk/src/types/block/input/utxo.rs
index 2c5616bf3b..bcd07ff96d 100644
--- a/sdk/src/types/block/input/utxo.rs
+++ b/sdk/src/types/block/input/utxo.rs
@@ -47,8 +47,6 @@ impl core::fmt::Debug for UtxoInput {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/macro.rs b/sdk/src/types/block/macro.rs
index 850537287d..1c1ffe85b2 100644
--- a/sdk/src/types/block/macro.rs
+++ b/sdk/src/types/block/macro.rs
@@ -177,7 +177,7 @@ macro_rules! impl_serde_typed_dto {
             fn deserialize<D: serde::Deserializer<'de>>(d: D) -> Result<Self, D::Error> {
                 let dto = <$dto>::deserialize(d)?;
                 if dto.kind != Self::KIND {
-                    return Err(serde::de::Error::custom(format!(
+                    return Err(serde::de::Error::custom(alloc::format!(
                         "invalid {} type: expected {}, found {}",
                         $type_str,
                         Self::KIND,
diff --git a/sdk/src/types/block/output/feature/block_issuer.rs b/sdk/src/types/block/output/feature/block_issuer.rs
new file mode 100644
index 0000000000..e7f8bad8c2
--- /dev/null
+++ b/sdk/src/types/block/output/feature/block_issuer.rs
@@ -0,0 +1,97 @@
+// Copyright 2023 IOTA Stiftung
+// SPDX-License-Identifier: Apache-2.0
+
+use alloc::vec::Vec;
+
+use crate::types::block::{
+    public_key::{PublicKey, PublicKeys},
+    slot::SlotIndex,
+    Error,
+};
+
+/// This feature defines the public keys with which a signature from the containing
+/// account's Block Issuance Credit can be verified in order to burn Mana.
+#[derive(Clone, Debug, Eq, PartialEq, Hash, packable::Packable)]
+#[packable(unpack_error = Error)]
+pub struct BlockIssuerFeature {
+    /// The slot index at which the Block Issuer Feature expires and can be removed.
+    expiry_slot: SlotIndex,
+    /// The Block Issuer Keys.
+    public_keys: PublicKeys,
+}
+
+impl BlockIssuerFeature {
+    /// The [`Feature`](crate::types::block::output::Feature) kind of a [`BlockIssuerFeature`].
+    pub const KIND: u8 = 4;
+
+    /// Creates a new [`BlockIssuerFeature`].
+    #[inline(always)]
+    pub fn new(
+        expiry_slot: impl Into<SlotIndex>,
+        public_keys: impl IntoIterator<Item = PublicKey>,
+    ) -> Result<Self, Error> {
+        let public_keys = PublicKeys::from_vec(public_keys.into_iter().collect::<Vec<PublicKey>>())?;
+        Ok(Self {
+            expiry_slot: expiry_slot.into(),
+            public_keys,
+        })
+    }
+
+    /// Returns the Slot Index at which the Block Issuer Feature expires and can be removed.
+    pub fn expiry_slot(&self) -> SlotIndex {
+        self.expiry_slot
+    }
+
+    /// Returns the Block Issuer Keys.
+    pub fn public_keys(&self) -> &[PublicKey] {
+        &self.public_keys
+    }
+}
+
+mod dto {
+    use alloc::vec::Vec;
+
+    use serde::{Deserialize, Serialize};
+
+    use super::BlockIssuerFeature;
+    use crate::types::block::{
+        public_key::{dto::PublicKeyDto, PublicKey},
+        slot::SlotIndex,
+        Error,
+    };
+
+    #[derive(Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
+    #[serde(rename_all = "camelCase")]
+    struct BlockIssuerFeatureDto {
+        #[serde(rename = "type")]
+        kind: u8,
+        expiry_slot: SlotIndex,
+        keys: Vec<PublicKeyDto>,
+    }
+
+    impl From<&BlockIssuerFeature> for BlockIssuerFeatureDto {
+        fn from(value: &BlockIssuerFeature) -> Self {
+            Self {
+                kind: BlockIssuerFeature::KIND,
+                expiry_slot: value.expiry_slot,
+                keys: value.public_keys.iter().map(|key| key.into()).collect(),
+            }
+        }
+    }
+
+    impl TryFrom<BlockIssuerFeatureDto> for BlockIssuerFeature {
+        type Error = Error;
+
+        fn try_from(value: BlockIssuerFeatureDto) -> Result<Self, Self::Error> {
+            let keys = value
+                .keys
+                .into_iter()
+                .map(PublicKey::try_from)
+                .collect::<Result<Vec<PublicKey>, Error>>()?;
+
+            Self::new(value.expiry_slot, keys)
+        }
+    }
+
+    impl_serde_typed_dto!(BlockIssuerFeature, BlockIssuerFeatureDto, "block issuer feature");
+}
diff --git a/sdk/src/types/block/output/feature/issuer.rs b/sdk/src/types/block/output/feature/issuer.rs
index ed7db8f808..d4fa89a8d5 100644
--- a/sdk/src/types/block/output/feature/issuer.rs
+++ b/sdk/src/types/block/output/feature/issuer.rs
@@ -27,8 +27,6 @@ impl IssuerFeature {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/output/feature/metadata.rs b/sdk/src/types/block/output/feature/metadata.rs
index fdf9444f76..e5903a6d5b 100644
--- a/sdk/src/types/block/output/feature/metadata.rs
+++ b/sdk/src/types/block/output/feature/metadata.rs
@@ -75,7 +75,7 @@ impl core::fmt::Debug for MetadataFeature {
 }
 
 mod dto {
-    use alloc::{borrow::Cow, format};
+    use alloc::borrow::Cow;
 
     use serde::{Deserialize, Serialize};
 
diff --git a/sdk/src/types/block/output/feature/mod.rs b/sdk/src/types/block/output/feature/mod.rs
index b9430bbe7b..6f766fa933 100644
--- a/sdk/src/types/block/output/feature/mod.rs
+++ b/sdk/src/types/block/output/feature/mod.rs
@@ -1,6 +1,7 @@
 // Copyright 2021-2022 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
+mod block_issuer;
 mod issuer;
 mod metadata;
 mod sender;
@@ -15,7 +16,8 @@ use iterator_sorted::is_unique_sorted;
 use packable::{bounded::BoundedU8, prefix::BoxedSlicePrefix, Packable};
 
 pub use self::{
-    issuer::IssuerFeature, metadata::MetadataFeature, sender::SenderFeature, staking::StakingFeature, tag::TagFeature,
+    block_issuer::BlockIssuerFeature, issuer::IssuerFeature, metadata::MetadataFeature, sender::SenderFeature,
+    staking::StakingFeature, tag::TagFeature,
 };
 pub(crate) use self::{metadata::MetadataFeatureLength, tag::TagFeatureLength};
 use crate::types::block::{create_bitflags, Error};
@@ -38,6 +40,9 @@ pub enum Feature {
     /// A tag feature.
     #[packable(tag = TagFeature::KIND)]
     Tag(TagFeature),
+    /// A block issuer feature.
+    #[packable(tag = BlockIssuerFeature::KIND)]
+    BlockIssuer(BlockIssuerFeature),
     /// A staking feature.
     #[packable(tag = StakingFeature::KIND)]
     Staking(StakingFeature),
@@ -62,6 +67,7 @@ impl core::fmt::Debug for Feature {
             Self::Issuer(feature) => feature.fmt(f),
             Self::Metadata(feature) => feature.fmt(f),
             Self::Tag(feature) => feature.fmt(f),
+            Self::BlockIssuer(feature) => feature.fmt(f),
             Self::Staking(feature) => feature.fmt(f),
         }
     }
@@ -75,6 +81,7 @@ impl Feature {
             Self::Issuer(_) => IssuerFeature::KIND,
             Self::Metadata(_) => MetadataFeature::KIND,
             Self::Tag(_) => TagFeature::KIND,
+            Self::BlockIssuer(_) => BlockIssuerFeature::KIND,
             Self::Staking(_) => StakingFeature::KIND,
         }
     }
@@ -86,6 +93,7 @@ impl Feature {
             Self::Issuer(_) => FeatureFlags::ISSUER,
             Self::Metadata(_) => FeatureFlags::METADATA,
             Self::Tag(_) => FeatureFlags::TAG,
+            Self::BlockIssuer(_) => FeatureFlags::BLOCK_ISSUER,
             Self::Staking(_) => FeatureFlags::STAKING,
         }
     }
@@ -150,6 +158,21 @@ impl Feature {
         }
     }
 
+    /// Checks whether the feature is a [`BlockIssuerFeature`].
+    pub fn is_block_issuer(&self) -> bool {
+        matches!(self, Self::BlockIssuer(_))
+    }
+
+    /// Gets the feature as an actual [`BlockIssuerFeature`].
+    /// NOTE: Will panic if the feature is not a [`BlockIssuerFeature`].
+    pub fn as_block_issuer(&self) -> &BlockIssuerFeature {
+        if let Self::BlockIssuer(feature) = self {
+            feature
+        } else {
+            panic!("invalid downcast of non-BlockIssuerFeature");
+        }
+    }
+
     /// Checks whether the feature is a [`StakingFeature`].
     pub fn is_staking(&self) -> bool {
         matches!(self, Self::Staking(_))
@@ -175,6 +198,7 @@ create_bitflags!(
         (ISSUER, IssuerFeature),
         (METADATA, MetadataFeature),
         (TAG, TagFeature),
+        (BLOCK_ISSUER, BlockIssuerFeature),
         (STAKING, StakingFeature),
     ]
 );
@@ -270,6 +294,11 @@ impl Features {
         self.get(TagFeature::KIND).map(Feature::as_tag)
     }
 
+    /// Gets a reference to a [`BlockIssuerFeature`], if any.
+    pub fn block_issuer(&self) -> Option<&BlockIssuerFeature> {
+        self.get(BlockIssuerFeature::KIND).map(Feature::as_block_issuer)
+    }
+
     /// Gets a reference to a [`StakingFeature`], if any.
     pub fn staking(&self) -> Option<&StakingFeature> {
         self.get(StakingFeature::KIND).map(Feature::as_staking)
@@ -311,6 +340,7 @@ mod test {
                 FeatureFlags::ISSUER,
                 FeatureFlags::METADATA,
                 FeatureFlags::TAG,
+                FeatureFlags::BLOCK_ISSUER,
                 FeatureFlags::STAKING
             ]
         );
diff --git a/sdk/src/types/block/output/feature/sender.rs b/sdk/src/types/block/output/feature/sender.rs
index 7094ef67c3..6ce4a11f74 100644
--- a/sdk/src/types/block/output/feature/sender.rs
+++ b/sdk/src/types/block/output/feature/sender.rs
@@ -27,8 +27,6 @@ impl SenderFeature {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/output/feature/staking.rs b/sdk/src/types/block/output/feature/staking.rs
index 04acdbd76c..97f52f7e6b 100644
--- a/sdk/src/types/block/output/feature/staking.rs
+++ b/sdk/src/types/block/output/feature/staking.rs
@@ -50,8 +50,6 @@ impl StakingFeature {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/output/feature/tag.rs b/sdk/src/types/block/output/feature/tag.rs
index ffa192664c..bd47355a15 100644
--- a/sdk/src/types/block/output/feature/tag.rs
+++ b/sdk/src/types/block/output/feature/tag.rs
@@ -67,7 +67,7 @@ impl core::fmt::Debug for TagFeature {
 }
 
 mod dto {
-    use alloc::{borrow::Cow, format};
+    use alloc::borrow::Cow;
 
     use serde::{Deserialize, Serialize};
 
diff --git a/sdk/src/types/block/output/token_scheme/simple.rs b/sdk/src/types/block/output/token_scheme/simple.rs
index 0c186ea96e..90df5693a5 100644
--- a/sdk/src/types/block/output/token_scheme/simple.rs
+++ b/sdk/src/types/block/output/token_scheme/simple.rs
@@ -117,8 +117,6 @@ fn verify_supply(minted_tokens: &U256, melted_tokens: &U256, maximum_supply: &U2
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/output/unlock_condition/address.rs b/sdk/src/types/block/output/unlock_condition/address.rs
index 1017ba58a6..b8cae1622d 100644
--- a/sdk/src/types/block/output/unlock_condition/address.rs
+++ b/sdk/src/types/block/output/unlock_condition/address.rs
@@ -27,8 +27,6 @@ impl AddressUnlockCondition {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/output/unlock_condition/expiration.rs b/sdk/src/types/block/output/unlock_condition/expiration.rs
index bc9711937b..ef2d40b075 100644
--- a/sdk/src/types/block/output/unlock_condition/expiration.rs
+++ b/sdk/src/types/block/output/unlock_condition/expiration.rs
@@ -65,8 +65,6 @@ fn verify_timestamp<const VERIFY: bool>(timestamp: &u32, _: &()) -> Result<(), E
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/output/unlock_condition/governor_address.rs b/sdk/src/types/block/output/unlock_condition/governor_address.rs
index 4abc7d6a56..11769d73dd 100644
--- a/sdk/src/types/block/output/unlock_condition/governor_address.rs
+++ b/sdk/src/types/block/output/unlock_condition/governor_address.rs
@@ -29,8 +29,6 @@ impl GovernorAddressUnlockCondition {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/output/unlock_condition/immutable_account_address.rs b/sdk/src/types/block/output/unlock_condition/immutable_account_address.rs
index 4bc11ee4da..86c71de764 100644
--- a/sdk/src/types/block/output/unlock_condition/immutable_account_address.rs
+++ b/sdk/src/types/block/output/unlock_condition/immutable_account_address.rs
@@ -27,8 +27,6 @@ impl ImmutableAccountAddressUnlockCondition {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/output/unlock_condition/state_controller_address.rs b/sdk/src/types/block/output/unlock_condition/state_controller_address.rs
index c820a94214..54d44ccbfc 100644
--- a/sdk/src/types/block/output/unlock_condition/state_controller_address.rs
+++ b/sdk/src/types/block/output/unlock_condition/state_controller_address.rs
@@ -29,8 +29,6 @@ impl StateControllerAddressUnlockCondition {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/output/unlock_condition/timelock.rs b/sdk/src/types/block/output/unlock_condition/timelock.rs
index 42a62e981f..b2d60ef002 100644
--- a/sdk/src/types/block/output/unlock_condition/timelock.rs
+++ b/sdk/src/types/block/output/unlock_condition/timelock.rs
@@ -39,8 +39,6 @@ fn verify_timestamp<const VERIFY: bool>(timestamp: &u32, _: &()) -> Result<(), E
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/payload/tagged_data/mod.rs b/sdk/src/types/block/payload/tagged_data/mod.rs
index 6c06c49498..abef88eb82 100644
--- a/sdk/src/types/block/payload/tagged_data/mod.rs
+++ b/sdk/src/types/block/payload/tagged_data/mod.rs
@@ -68,8 +68,6 @@ impl core::fmt::Debug for TaggedDataPayload {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/public_key/mod.rs b/sdk/src/types/block/public_key/mod.rs
index 38f8b67836..02acb3d8e8 100644
--- a/sdk/src/types/block/public_key/mod.rs
+++ b/sdk/src/types/block/public_key/mod.rs
@@ -3,12 +3,18 @@
 
 mod ed25519;
 
-use derive_more::From;
+use alloc::{boxed::Box, collections::BTreeSet, vec::Vec};
+use core::ops::RangeInclusive;
+
+use derive_more::{Deref, From};
+use iterator_sorted::is_unique_sorted;
+use packable::{bounded::BoundedU8, prefix::BoxedSlicePrefix, Packable};
 
 pub use self::ed25519::Ed25519PublicKey;
 use crate::types::block::Error;
 
 #[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Hash, From, packable::Packable)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize), serde(untagged))]
 #[packable(unpack_error = Error)]
 #[packable(tag_type = u8, with_error = Error::InvalidPublicKeyKind)]
 pub enum PublicKey {
@@ -77,3 +83,77 @@ pub(crate) mod dto {
         }
     }
 }
+
+pub(crate) type PublicKeyCount = BoundedU8<{ *PublicKeys::COUNT_RANGE.start() }, { *PublicKeys::COUNT_RANGE.end() }>;
+
+/// Lexicographically ordered list of unique [`PublicKey`]
+#[derive(Clone, Debug, Eq, PartialEq, Deref, Packable, Hash)]
+#[packable(unpack_error = Error, with = |e| e.unwrap_item_err_or_else(|p| Error::InvalidPublicKeyCount(p.into())))]
+pub struct PublicKeys(#[packable(verify_with = verify_public_keys)] BoxedSlicePrefix<PublicKey, PublicKeyCount>);
+
+fn verify_public_keys<const VERIFY: bool>(public_keys: &[PublicKey], _visitor: &()) -> Result<(), Error> {
+    if VERIFY && !is_unique_sorted(public_keys.iter()) {
+        return Err(Error::PublicKeysNotUniqueSorted);
+    }
+
+    Ok(())
+}
+
+impl TryFrom<Vec<PublicKey>> for PublicKeys {
+    type Error = Error;
+
+    #[inline(always)]
+    fn try_from(public_keys: Vec<PublicKey>) -> Result<Self, Self::Error> {
+        Self::from_vec(public_keys)
+    }
+}
+
+impl TryFrom<BTreeSet<PublicKey>> for PublicKeys {
+    type Error = Error;
+
+    #[inline(always)]
+    fn try_from(public_keys: BTreeSet<PublicKey>) -> Result<Self, Self::Error> {
+        Self::from_set(public_keys)
+    }
+}
+
+impl IntoIterator for PublicKeys {
+    type Item = PublicKey;
+    type IntoIter = alloc::vec::IntoIter<Self::Item>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        Vec::from(Into::<Box<[PublicKey]>>::into(self.0)).into_iter()
+    }
+}
+
+impl PublicKeys {
+    /// The minimum number of public_keys of a transaction.
+    pub const COUNT_MIN: u8 = 1;
+    /// The maximum number of public_keys of a transaction.
+    pub const COUNT_MAX: u8 = 128;
+    /// The range of valid numbers of public_keys.
+    pub const COUNT_RANGE: RangeInclusive<u8> = Self::COUNT_MIN..=Self::COUNT_MAX; // [1..128]
+
+    /// Creates a new [`PublicKeys`] from a vec.
+    pub fn from_vec(public_keys: Vec<PublicKey>) -> Result<Self, Error> {
+        let mut public_keys = BoxedSlicePrefix::<PublicKey, PublicKeyCount>::try_from(public_keys.into_boxed_slice())
+            .map_err(Error::InvalidPublicKeyCount)?;
+
+        public_keys.sort();
+
+        // Still need to verify the duplicate public keys.
+        verify_public_keys::<true>(&public_keys, &())?;
+
+        Ok(Self(public_keys))
+    }
+
+    /// Creates a new [`PublicKeys`] from an ordered set.
+    pub fn from_set(public_keys: BTreeSet<PublicKey>) -> Result<Self, Error> {
+        let public_keys =
+            BoxedSlicePrefix::<PublicKey, PublicKeyCount>::try_from(public_keys.into_iter().collect::<Box<[_]>>())
+                .map_err(Error::InvalidPublicKeyCount)?;
+
+        // We don't need to verify the public keys here, because they are already verified by the BTreeSet.
+        Ok(Self(public_keys))
+    }
+}
diff --git a/sdk/src/types/block/rand/mod.rs b/sdk/src/types/block/rand/mod.rs
index 9cac72a1fe..9b5564ef2e 100644
--- a/sdk/src/types/block/rand/mod.rs
+++ b/sdk/src/types/block/rand/mod.rs
@@ -21,6 +21,8 @@ pub mod output;
 pub mod parents;
 /// Module providing random payload generation utilities.
 pub mod payload;
+/// Module providing random public key generation utilities.
+pub mod public_key;
 /// Module providing random signature generation utilities.
 pub mod signature;
 /// Module providing random slot generation utilities.
diff --git a/sdk/src/types/block/rand/output/feature.rs b/sdk/src/types/block/rand/output/feature.rs
index 3b41389a63..fcdc6ad92b 100644
--- a/sdk/src/types/block/rand/output/feature.rs
+++ b/sdk/src/types/block/rand/output/feature.rs
@@ -5,12 +5,15 @@ use alloc::vec::Vec;
 
 use crate::types::block::{
     output::feature::{
-        Feature, FeatureFlags, IssuerFeature, MetadataFeature, SenderFeature, StakingFeature, TagFeature,
+        BlockIssuerFeature, Feature, FeatureFlags, IssuerFeature, MetadataFeature, SenderFeature, StakingFeature,
+        TagFeature,
     },
+    public_key::PublicKeys,
     rand::{
         address::rand_address,
         bytes::rand_bytes,
         number::{rand_number, rand_number_range},
+        public_key::rand_public_keys,
     },
 };
 
@@ -36,6 +39,19 @@ pub fn rand_tag_feature() -> TagFeature {
     TagFeature::new(bytes).unwrap()
 }
 
+/// Generates a random [`BlockIssuerFeature`].
+pub fn rand_block_issuer_feature() -> BlockIssuerFeature {
+    BlockIssuerFeature::new(
+        rand_number::<u64>(),
+        rand_public_keys(rand_number_range(
+            PublicKeys::COUNT_MIN as usize..=PublicKeys::COUNT_MAX as usize,
+        ))
+        .into_iter()
+        .collect::<Vec<_>>(),
+    )
+    .unwrap()
+}
+
 /// Generates a random [`StakingFeature`].
 pub fn rand_staking_feature() -> StakingFeature {
     StakingFeature::new(rand_number(), rand_number(), rand_number(), rand_number())
@@ -47,6 +63,7 @@ fn rand_feature_from_flag(flag: &FeatureFlags) -> Feature {
         FeatureFlags::ISSUER => Feature::Issuer(rand_issuer_feature()),
         FeatureFlags::METADATA => Feature::Metadata(rand_metadata_feature()),
         FeatureFlags::TAG => Feature::Tag(rand_tag_feature()),
+        FeatureFlags::BLOCK_ISSUER => Feature::BlockIssuer(rand_block_issuer_feature()),
         FeatureFlags::STAKING => Feature::Staking(rand_staking_feature()),
         _ => unreachable!(),
     }
diff --git a/sdk/src/types/block/rand/public_key.rs b/sdk/src/types/block/rand/public_key.rs
new file mode 100644
index 0000000000..6158e3d6b4
--- /dev/null
+++ b/sdk/src/types/block/rand/public_key.rs
@@ -0,0 +1,26 @@
+// Copyright 2023 IOTA Stiftung
+// SPDX-License-Identifier: Apache-2.0
+
+use alloc::collections::BTreeSet;
+
+use crate::types::block::public_key::{Ed25519PublicKey, PublicKey};
+
+/// Generates a valid random Ed25519 public key.
+pub fn rand_ed25519_public_key() -> Ed25519PublicKey {
+    let key = crypto::signatures::ed25519::SecretKey::generate().unwrap();
+    key.public_key().into()
+}
+
+/// Generates a valid random public key.
+pub fn rand_public_key() -> PublicKey {
+    rand_ed25519_public_key().into()
+}
+
+/// Generates a vector of random valid public keys of a given length.
+pub fn rand_public_keys(len: usize) -> BTreeSet<PublicKey> {
+    let mut public_keys: BTreeSet<PublicKey> = BTreeSet::new();
+    while public_keys.len() < len {
+        public_keys.insert(rand_public_key());
+    }
+    public_keys
+}
diff --git a/sdk/src/types/block/signature/ed25519.rs b/sdk/src/types/block/signature/ed25519.rs
index 959a5ca5f0..676d481698 100644
--- a/sdk/src/types/block/signature/ed25519.rs
+++ b/sdk/src/types/block/signature/ed25519.rs
@@ -128,7 +128,7 @@ impl Packable for Ed25519Signature {
 }
 
 mod dto {
-    use alloc::{format, string::String};
+    use alloc::string::String;
 
     use serde::{Deserialize, Serialize};
 
diff --git a/sdk/src/types/block/slot/index.rs b/sdk/src/types/block/slot/index.rs
index 8d92a4f5a1..27d62fee89 100644
--- a/sdk/src/types/block/slot/index.rs
+++ b/sdk/src/types/block/slot/index.rs
@@ -16,5 +16,11 @@ impl SlotIndex {
     }
 }
 
+impl From<SlotIndex> for u64 {
+    fn from(slot_index: SlotIndex) -> Self {
+        *slot_index
+    }
+}
+
 #[cfg(feature = "serde")]
 string_serde_impl!(SlotIndex);
diff --git a/sdk/src/types/block/unlock/account.rs b/sdk/src/types/block/unlock/account.rs
index e496be7d3b..4a301733b9 100644
--- a/sdk/src/types/block/unlock/account.rs
+++ b/sdk/src/types/block/unlock/account.rs
@@ -37,8 +37,6 @@ impl AccountUnlock {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/unlock/nft.rs b/sdk/src/types/block/unlock/nft.rs
index 30ebd89a05..d7c114a9ca 100644
--- a/sdk/src/types/block/unlock/nft.rs
+++ b/sdk/src/types/block/unlock/nft.rs
@@ -37,8 +37,6 @@ impl NftUnlock {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/unlock/reference.rs b/sdk/src/types/block/unlock/reference.rs
index 2d5a52957b..3499cb0d67 100644
--- a/sdk/src/types/block/unlock/reference.rs
+++ b/sdk/src/types/block/unlock/reference.rs
@@ -34,8 +34,6 @@ impl ReferenceUnlock {
 }
 
 mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;
diff --git a/sdk/src/types/block/unlock/signature.rs b/sdk/src/types/block/unlock/signature.rs
index 3047f76113..fdacd2549e 100644
--- a/sdk/src/types/block/unlock/signature.rs
+++ b/sdk/src/types/block/unlock/signature.rs
@@ -28,8 +28,6 @@ impl SignatureUnlock {
 }
 
 pub(crate) mod dto {
-    use alloc::format;
-
     use serde::{Deserialize, Serialize};
 
     use super::*;