diff --git a/Cargo.lock b/Cargo.lock
index 2232476f7..4e43c426e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -650,7 +650,7 @@ dependencies = [
  "grin_wallet 0.3.0",
  "lmdb-zero 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "lru-cache 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "slog 2.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -688,7 +688,7 @@ dependencies = [
  "lazy_static 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lru-cache 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-bigint 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "siphasher 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -702,7 +702,7 @@ dependencies = [
  "blake2-rfc 0.2.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "grin_util 0.3.0",
- "rand 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rust-crypto 0.2.36 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -726,7 +726,7 @@ dependencies = [
  "lmdb-zero 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "net2 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)",
  "num 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "slog 2.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -744,7 +744,7 @@ dependencies = [
  "grin_store 0.3.0",
  "grin_util 0.3.0",
  "grin_wallet 0.3.0",
- "rand 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "slog 2.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -774,7 +774,7 @@ dependencies = [
  "itertools 0.7.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-core 8.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "lmdb-zero 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -796,7 +796,7 @@ dependencies = [
  "libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)",
  "lmdb-zero 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "memmap 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "slog 2.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -809,8 +809,8 @@ dependencies = [
  "backtrace 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
- "secp256k1zkp 0.7.1 (git+https://github.com/mimblewimble/rust-secp256k1-zkp?tag=grin_integration_23)",
+ "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "secp256k1zkp 0.7.1 (git+https://github.com/mimblewimble/rust-secp256k1-zkp?tag=grin_integration_23a)",
  "serde 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "slog 2.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -838,7 +838,7 @@ dependencies = [
  "grin_util 0.3.0",
  "hyper 0.12.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "prettytable-rs 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1836,12 +1836,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "secp256k1zkp"
 version = "0.7.1"
-source = "git+https://github.com/mimblewimble/rust-secp256k1-zkp?tag=grin_integration_23#6f599fcc17b98340d0c4c9d87cc48d51f29d3816"
+source = "git+https://github.com/mimblewimble/rust-secp256k1-zkp?tag=grin_integration_23a#0248d26f309ec7b1da0b0944de62a96cdef51fbd"
 dependencies = [
  "arrayvec 0.3.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "gcc 0.3.54 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.79 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2726,7 +2726,7 @@ dependencies = [
 "checksum schannel 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "dc1fabf2a7b6483a141426e1afd09ad543520a77ac49bd03c286e7696ccfd77f"
 "checksum scoped-tls 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "332ffa32bf586782a3efaeb58f127980944bbc8c4d6913a86107ac2a5ab24b28"
 "checksum scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "94258f53601af11e6a49f722422f6e3425c52b06245a5cf9bc09908b174f5e27"
-"checksum secp256k1zkp 0.7.1 (git+https://github.com/mimblewimble/rust-secp256k1-zkp?tag=grin_integration_23)" = "<none>"
+"checksum secp256k1zkp 0.7.1 (git+https://github.com/mimblewimble/rust-secp256k1-zkp?tag=grin_integration_23a)" = "<none>"
 "checksum security-framework 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)" = "dfa44ee9c54ce5eecc9de7d5acbad112ee58755239381f687e564004ba4a2332"
 "checksum security-framework-sys 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)" = "5421621e836278a0b139268f36eee0dc7e389b784dc3f79d8f11aabadf41bead"
 "checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
diff --git a/chain/Cargo.toml b/chain/Cargo.toml
index 3771a16af..ac543e565 100644
--- a/chain/Cargo.toml
+++ b/chain/Cargo.toml
@@ -26,4 +26,4 @@ grin_util = { path = "../util" }
 [dev-dependencies]
 grin_wallet = { path = "../wallet" }
 env_logger = "0.5"
-rand = "0.3"
+rand = "0.5"
diff --git a/core/Cargo.toml b/core/Cargo.toml
index fb1e2edc0..ba46283d7 100644
--- a/core/Cargo.toml
+++ b/core/Cargo.toml
@@ -15,7 +15,7 @@ failure_derive = "0.1"
 lazy_static = "1"
 lru-cache = "0.1"
 num-bigint = "0.2"
-rand = "0.3"
+rand = "0.5"
 serde = "1"
 serde_derive = "1"
 siphasher = "0.2"
diff --git a/core/src/core/compact_block.rs b/core/src/core/compact_block.rs
index eb0b1b1c7..eb23c15fe 100644
--- a/core/src/core/compact_block.rs
+++ b/core/src/core/compact_block.rs
@@ -14,7 +14,7 @@
 
 //! Compact Blocks.
 
-use rand::{thread_rng, Rng};
+use rand::{thread_rng, RngCore};
 
 use consensus::VerifySortOrder;
 use core::block::{Block, BlockHeader, Error};
diff --git a/keychain/Cargo.toml b/keychain/Cargo.toml
index 506a26df6..495f655c0 100644
--- a/keychain/Cargo.toml
+++ b/keychain/Cargo.toml
@@ -8,7 +8,7 @@ publish = false
 [dependencies]
 byteorder = "1"
 blake2-rfc = "0.2"
-rand = "0.3"
+rand = "0.5"
 slog = { version = "~2.3", features = ["max_level_trace", "release_max_level_trace"] }
 serde = "1"
 serde_derive = "1"
diff --git a/keychain/src/keychain.rs b/keychain/src/keychain.rs
index 248a2aeab..fc2fba9fb 100644
--- a/keychain/src/keychain.rs
+++ b/keychain/src/keychain.rs
@@ -14,6 +14,7 @@
 
 /// Implementation of the Keychain trait based on an extended key derivation
 /// scheme.
+use rand::distributions::Alphanumeric;
 use rand::{thread_rng, Rng};
 use std::collections::HashMap;
 use std::sync::{Arc, RwLock};
@@ -50,7 +51,7 @@ impl Keychain for ExtKeychain {
 
 	/// For testing - probably not a good idea to use outside of tests.
 	fn from_random_seed() -> Result<ExtKeychain, Error> {
-		let seed: String = thread_rng().gen_ascii_chars().take(16).collect();
+		let seed: String = thread_rng().sample_iter(&Alphanumeric).take(16).collect();
 		let seed = blake2::blake2b::blake2b(32, &[], seed.as_bytes());
 		ExtKeychain::from_seed(seed.as_bytes())
 	}
diff --git a/p2p/Cargo.toml b/p2p/Cargo.toml
index fc1457d1e..a02561d4a 100644
--- a/p2p/Cargo.toml
+++ b/p2p/Cargo.toml
@@ -12,7 +12,7 @@ enum_primitive = "0.1"
 lmdb-zero = "0.4.4"
 net2 = "0.2"
 num = "0.1"
-rand = "0.3"
+rand = "0.5"
 serde = "1"
 serde_derive = "1"
 slog = { version = "~2.3", features = ["max_level_trace", "release_max_level_trace"] }
diff --git a/p2p/src/handshake.rs b/p2p/src/handshake.rs
index e69a248cf..03553111f 100644
--- a/p2p/src/handshake.rs
+++ b/p2p/src/handshake.rs
@@ -17,7 +17,7 @@ use std::net::{SocketAddr, TcpStream};
 use std::sync::{Arc, RwLock};
 
 use rand::os::OsRng;
-use rand::Rng;
+use rand::RngCore;
 
 use core::core::hash::Hash;
 use core::core::target::Difficulty;
diff --git a/pool/Cargo.toml b/pool/Cargo.toml
index 1bc03e3ed..147a8839c 100644
--- a/pool/Cargo.toml
+++ b/pool/Cargo.toml
@@ -7,7 +7,7 @@ publish = false
 
 [dependencies]
 blake2-rfc = "0.2"
-rand = "0.3"
+rand = "0.5"
 serde = "1"
 serde_derive = "1"
 slog = { version = "~2.3", features = ["max_level_trace", "release_max_level_trace"] }
diff --git a/servers/Cargo.toml b/servers/Cargo.toml
index 1a23bfe56..715c5d755 100644
--- a/servers/Cargo.toml
+++ b/servers/Cargo.toml
@@ -12,7 +12,7 @@ http = "0.1"
 hyper-staticfile = "0.3"
 itertools = "0.7"
 lmdb-zero = "0.4.4"
-rand = "0.3"
+rand = "0.5"
 slog = { version = "~2.3", features = ["max_level_trace", "release_max_level_trace"] }
 serde = "1"
 serde_derive = "1"
diff --git a/store/Cargo.toml b/store/Cargo.toml
index 70ac31c35..bab58e345 100644
--- a/store/Cargo.toml
+++ b/store/Cargo.toml
@@ -23,4 +23,4 @@ grin_util = { path = "../util" }
 
 [dev-dependencies]
 chrono = "0.4.4"
-rand = "0.3"
+rand = "0.5"
diff --git a/util/Cargo.toml b/util/Cargo.toml
index ae2200dc8..4322ebe0d 100644
--- a/util/Cargo.toml
+++ b/util/Cargo.toml
@@ -9,7 +9,7 @@ publish = false
 backtrace = "0.3"
 byteorder = "1"
 lazy_static = "1"
-rand = "0.3"
+rand = "0.5"
 serde = "1"
 serde_derive = "1"
 slog = { version = "~2.3", features = ["max_level_trace", "release_max_level_trace"] }
@@ -20,6 +20,6 @@ zip = "0.4"
 
 [dependencies.secp256k1zkp]
 git = "https://github.com/mimblewimble/rust-secp256k1-zkp"
-tag = "grin_integration_23"
+tag = "grin_integration_23a"
 #path = "../../rust-secp256k1-zkp"
 features = ["bullet-proof-sizing"]
diff --git a/wallet/Cargo.toml b/wallet/Cargo.toml
index 80d412df4..cbc8b7b88 100644
--- a/wallet/Cargo.toml
+++ b/wallet/Cargo.toml
@@ -13,7 +13,7 @@ failure_derive = "0.1"
 futures = "0.1"
 hyper = "0.12"
 prettytable-rs = "0.7"
-rand = "0.3"
+rand = "0.5"
 serde = "1"
 serde_derive = "1"
 serde_json = "1"