diff --git a/Cargo.lock b/Cargo.lock
index dbaa65c2965..39d91bd2bba 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -58,6 +58,11 @@ name = "arc-swap"
 version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "arrayref"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "arrayvec"
 version = "0.4.12"
@@ -66,6 +71,11 @@ dependencies = [
  "nodrop 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "arrayvec"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "autocfg"
 version = "0.1.7"
@@ -109,6 +119,16 @@ name = "bitflags"
 version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "blake2b_simd"
+version = "0.5.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "arrayref 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "arrayvec 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "constant_time_eq 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "block-buffer"
 version = "0.7.3"
@@ -128,6 +148,14 @@ dependencies = [
  "byte-tools 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "bls12_381"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "subtle 2.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "byte-tools"
 version = "0.3.1"
@@ -189,6 +217,11 @@ dependencies = [
  "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "constant_time_eq"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "crossbeam-channel"
 version = "0.3.9"
@@ -535,6 +568,15 @@ name = "itoa"
 version = "0.4.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "jubjub"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bls12_381 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "subtle 2.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "kernel32-sys"
 version = "0.2.2"
@@ -934,6 +976,18 @@ dependencies = [
  "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "redjubjub"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "blake2b_simd 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jubjub 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.103 (registry+https://github.com/rust-lang/crates.io-index)",
+ "thiserror 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.1.56"
@@ -1105,6 +1159,11 @@ name = "strsim"
 version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "subtle"
+version = "2.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "syn"
 version = "0.15.44"
@@ -1659,6 +1718,7 @@ dependencies = [
  "chrono 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "proptest 0.9.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "redjubjub 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sha2 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "thiserror 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -1742,15 +1802,19 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum aho-corasick 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)" = "58fb5e95d83b38284460a5fda7d6470aa0b8844d283a0b614b8535e880800d2d"
 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
 "checksum arc-swap 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "f1a1eca3195b729bbd64e292ef2f5fff6b1c28504fed762ce2b1013dde4d8e92"
+"checksum arrayref 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "0d382e583f07208808f6b1249e60848879ba3543f57c32277bf52d69c2f0f0ee"
 "checksum arrayvec 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)" = "cd9fd44efafa8690358b7408d253adf110036b88f55672a933f01d616ad9b1b9"
+"checksum arrayvec 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cff77d8686867eceff3105329d4698d96c2391c176d5d03adc90c7389162b5b8"
 "checksum autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "1d49d90015b3c36167a20fe2810c5cd875ad504b39cff3d4eae7977e6b7c1cb2"
 "checksum backtrace 0.3.40 (registry+https://github.com/rust-lang/crates.io-index)" = "924c76597f0d9ca25d762c25a4d369d51267536465dc5064bdf0eb073ed477ea"
 "checksum backtrace-sys 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)" = "5d6575f128516de27e3ce99689419835fce9643a9b215a14d2b5b685be018491"
 "checksum bit-set 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e84c238982c4b1e1ee668d136c510c67a13465279c0cb367ea6baf6310620a80"
 "checksum bit-vec 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "f59bbe95d4e52a6398ec21238d31577f2b28a9d86807f06ca59d191d8440d0bb"
 "checksum bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
+"checksum blake2b_simd 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)" = "b83b7baab1e671718d78204225800d6b170e648188ac7dc992e9d6bddf87d0c0"
 "checksum block-buffer 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)" = "c0940dc441f31689269e10ac70eb1002a3a1d3ad1390e030043662eb7fe4688b"
 "checksum block-padding 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "6d4dc3af3ee2e12f3e5d224e5e1e3d73668abbeb69e566d361f7d5563a4fdf09"
+"checksum bls12_381 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c8586926bfacc9d548769ecd480d31f35fc3158e9650637b514e98f13659a620"
 "checksum byte-tools 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e3b5ca7a04898ad4bcd41c90c5285445ff5b791899bb1b0abdd2a2aa791211d7"
 "checksum byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a7c3dd8985a7111efc5c80b44e23ecdd8c007de8ade3b96595387e812b957cf5"
 "checksum bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)" = "206fdffcfa2df7cbe15601ef46c813fce0965eb3286db6b56c583b814b51c81c"
@@ -1760,6 +1824,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 "checksum chrono 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)" = "31850b4a4d6bae316f7a09e691c944c28299298837edc0a03f755618c23cbc01"
 "checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
+"checksum constant_time_eq 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "995a44c877f9212528ccc74b21a232f66ad69001e40ede5bcee2ac9ef2657120"
 "checksum crossbeam-channel 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "c8ec7fcd21571dc78f96cc96243cab8d8f035247c3efd16c687be154c3fa9efa"
 "checksum crossbeam-deque 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b18cd2e169ad86297e6bc0ad9aa679aee9daa4f19e8163860faf7c164e4f5a71"
 "checksum crossbeam-epoch 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "fedcd6772e37f3da2a9af9bf12ebe046c0dfe657992377b4df982a2b54cd37a9"
@@ -1798,6 +1863,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum indexmap 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712d7b3ea5827fcb9d4fda14bf4da5f136f0db2ae9c8f4bd4e2d1c6fde4e6db2"
 "checksum iovec 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "b2b3ea6ff95e175473f8ffe6a7eb7c00d054240321b84c57051175fe3c1e075e"
 "checksum itoa 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)" = "501266b7edd0174f8530248f87f99c88fbe60ca4ef3dd486835b8d8d53136f7f"
+"checksum jubjub 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "aaacc6b2b5fa79a5bd49de8439534b1f98886f06b88da02afeb968d60678b978"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
 "checksum lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 "checksum libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)" = "1a31a0627fdf1f6a39ec0dd577e101440b7db22672c0901fe00a9a6fbb5c24e8"
@@ -1843,6 +1909,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum rand_pcg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "abf9b09b01790cfe0364f52bf32995ea3c39f4d2dd011eac241d2914146d0b44"
 "checksum rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cbf7e9e623549b0e21f6e97cf8ecf247c1a8fd2e8a992ae265314300b2455d5c"
 "checksum rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
+"checksum redjubjub 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7bdc0fe90e1f35b2dd4d6f838917ff0e8fee167c5eac501d110698deb516a534"
 "checksum redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)" = "2439c63f3f6139d1b57529d16bc3b8bb855230c8efcc5d3a896c8bea7c3b1e84"
 "checksum regex 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "dc220bd33bdce8f093101afe22a037b8eb0e5af33592e6a9caafff0d4cb81cbd"
 "checksum regex-automata 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "92b73c2a1770c255c240eaa4ee600df1704a38dc3feaa6e949e7fcd4f8dc09f9"
@@ -1866,6 +1933,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum stable_deref_trait 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "dba1a27d3efae4351c8051072d619e3ade2820635c3958d826bfea39d59b54c8"
 "checksum string 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "d24114bfcceb867ca7f71a0d3fe45d45619ec47a6fbfa98cb14e14250bfa5d6d"
 "checksum strsim 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bb4f380125926a99e52bc279241539c018323fab05ad6368b56f93d9369ff550"
+"checksum subtle 2.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7c65d530b10ccaeac294f349038a597e435b18fb456aadd0840a623f83b9e941"
 "checksum syn 0.15.44 (registry+https://github.com/rust-lang/crates.io-index)" = "9ca4b3b69a77cbe1ffc9e198781b7acb0c7365a883670e8f1c1bc66fba79a5c5"
 "checksum syn 1.0.11 (registry+https://github.com/rust-lang/crates.io-index)" = "dff0acdb207ae2fe6d5976617f887eb1e35a2ba52c13c7234c790960cdad9238"
 "checksum synstructure 0.10.2 (registry+https://github.com/rust-lang/crates.io-index)" = "02353edf96d6e4dc81aea2d8490a7e9db177bf8acb0e951c24940bf866cb313f"
diff --git a/zebra-chain/Cargo.toml b/zebra-chain/Cargo.toml
index 355aaa156da..606c3600d2f 100644
--- a/zebra-chain/Cargo.toml
+++ b/zebra-chain/Cargo.toml
@@ -13,6 +13,7 @@ byteorder = "1.3"
 chrono = "0.4"
 hex = "0.4"
 sha2 = "0.8"
+redjubjub = "0.1"
 
 [dev-dependencies]
 proptest = "0.9"
\ No newline at end of file
diff --git a/zebra-chain/src/lib.rs b/zebra-chain/src/lib.rs
index 76c79a6fdb3..a68a1127014 100644
--- a/zebra-chain/src/lib.rs
+++ b/zebra-chain/src/lib.rs
@@ -11,3 +11,5 @@ pub mod proofs;
 pub mod serialization;
 pub mod transaction;
 pub mod types;
+
+pub use redjubjub;
diff --git a/zebra-chain/src/transaction/shielded_data.rs b/zebra-chain/src/transaction/shielded_data.rs
index e00e56f4085..c47d57eaaec 100644
--- a/zebra-chain/src/transaction/shielded_data.rs
+++ b/zebra-chain/src/transaction/shielded_data.rs
@@ -1,6 +1,8 @@
 // XXX this name seems too long?
 use crate::note_commitment_tree::SaplingNoteTreeRootHash;
 
+use crate::redjubjub::{self, Binding, SpendAuth};
+
 /// A _Spend Description_, as described in [protocol specification §7.3][ps].
 ///
 /// [ps]: https://zips.z.cash/protocol/protocol.pdf#spendencoding
@@ -17,19 +19,14 @@ pub struct SpendDescription {
     /// XXX refine to a specific type.
     pub nullifier: [u8; 32],
     /// The randomized public key for `spend_auth_sig`.
-    ///
-    /// XXX refine to a specific type.
-    pub rk: [u8; 32],
+    pub rk: redjubjub::PublicKeyBytes<SpendAuth>,
     /// The ZK spend proof.
     ///
     /// XXX add proof types.
     /// XXX for now it's [u64; 24] instead of [u8; 192] to get trait impls
     pub zkproof: [u64; 24],
     /// A signature authorizing this spend.
-    ///
-    /// XXX refine to a specific type: redjubjub signature?
-    /// XXX for now it's [u64; 8] instead of [u8; 64] to get trait impls
-    pub spend_auth_sig: [u64; 8],
+    pub spend_auth_sig: redjubjub::Signature<SpendAuth>,
 }
 
 /// A _Output Description_, as described in [protocol specification §7.4][ps].
@@ -47,7 +44,7 @@ pub struct OutputDescription {
     pub cmu: [u8; 32],
     /// An encoding of an ephemeral Jubjub public key.
     ///
-    /// XXX refine to a specific type.
+    /// XXX refine to a Jubjub key agreement type, not RedJubjub.
     pub ephemeral_key: [u8; 32],
     /// A ciphertext component for the encrypted output note.
     ///
@@ -74,7 +71,5 @@ pub struct ShieldedData {
     /// A sequence of shielded outputs for this transaction.
     pub shielded_outputs: Vec<OutputDescription>,
     /// A signature on the transaction hash.
-    // XXX refine this type to a RedJubjub signature.
-    // for now it's [u64; 8] rather than [u8; 64] to get trait impls
-    pub binding_sig: [u64; 8],
+    pub binding_sig: redjubjub::Signature<Binding>,
 }