diff --git a/store/src/lib.rs b/store/src/lib.rs
index 5814bf6c..b2408ca5 100644
--- a/store/src/lib.rs
+++ b/store/src/lib.rs
@@ -32,6 +32,39 @@ pub mod pmmr;
 pub mod prune_list;
 pub mod types;
 
+const SEP: u8 = b':';
+
+use byteorder::{BigEndian, WriteBytesExt};
+
+/// Build a db key from a prefix and a byte vector identifier.
+pub fn to_key<K: AsRef<[u8]>>(prefix: u8, k: K) -> Vec<u8> {
+	let k = k.as_ref();
+	let mut res = Vec::with_capacity(k.len() + 2);
+	res.push(prefix);
+	res.push(SEP);
+	res.extend_from_slice(k);
+	res
+}
+
+/// Build a db key from a prefix and a byte vector identifier and numeric identifier
+pub fn to_key_u64<K: AsRef<[u8]>>(prefix: u8, k: K, val: u64) -> Vec<u8> {
+	let k = k.as_ref();
+	let mut res = Vec::with_capacity(k.len() + 10);
+	res.push(prefix);
+	res.push(SEP);
+	res.extend_from_slice(k);
+	res.write_u64::<BigEndian>(val).unwrap();
+	res
+}
+/// Build a db key from a prefix and a numeric identifier.
+pub fn u64_to_key(prefix: u8, val: u64) -> Vec<u8> {
+	let mut res = Vec::with_capacity(10);
+	res.push(prefix);
+	res.push(SEP);
+	res.write_u64::<BigEndian>(val).unwrap();
+	res
+}
+
 pub use crate::lmdb::*;
 
 use std::ffi::OsStr;