diff --git a/Cargo.lock b/Cargo.lock
index 74c989a..04a55ca 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4,11 +4,11 @@ version = 4
 
 [[package]]
 name = "block-buffer"
-version = "0.10.4"
+version = "0.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3078c7629b62d3f0439517fa394996acacc5cbc91c5a20d8c658e77abd503a71"
+checksum = "d2f6c7dbe95a6ed67ad9f18e57daf93a2f034c524b99fd2b76d18fdfeb6660aa"
 dependencies = [
- "generic-array",
+ "hybrid-array",
 ]
 
 [[package]]
@@ -17,43 +17,48 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
+[[package]]
+name = "const-oid"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a6ef517f0926dd24a1582492c791b6a4818a4d94e789a334894aa15b0d12f55c"
+
 [[package]]
 name = "cpufeatures"
-version = "0.2.17"
+version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "59ed5838eebb26a2bb2e58f6d5b5316989ae9d08bab10e0e6d103e656d1b0280"
+checksum = "5ca28b0ae3115b884660db4118d803791fd6756b6e88f39c0f3f7859060d7566"
 dependencies = [
  "libc",
 ]
 
 [[package]]
 name = "crypto-common"
-version = "0.1.7"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "78c8292055d1c1df0cce5d180393dc8cce0abec0a7102adb6c7b1eef6016d60a"
+checksum = "ce6e4c961d6cd6c9a86db418387425e8bdeaf05b3c8bc1411e6dca4c252f1453"
 dependencies = [
- "generic-array",
- "typenum",
+ "hybrid-array",
 ]
 
 [[package]]
 name = "digest"
-version = "0.10.7"
+version = "0.11.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
+checksum = "f1dd6dbb5841937940781866fa1281a1ff7bd3bf827091440879f9994983d5c2"
 dependencies = [
  "block-buffer",
+ "const-oid",
  "crypto-common",
 ]
 
 [[package]]
-name = "generic-array"
-version = "0.14.7"
+name = "hybrid-array"
+version = "0.4.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "85649ca51fd72272d7821adaf274ad91c288277713d9c18820d8499a7ff69e9a"
+checksum = "27f864f10dfb56725ce5ce5472bc52252c8f93a4ab86327122cebf62c5f59a17"
 dependencies = [
  "typenum",
- "version_check",
 ]
 
 [[package]]
@@ -160,9 +165,9 @@ dependencies = [
 
 [[package]]
 name = "sha2"
-version = "0.10.9"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a7507d819769d01a365ab707794a4084392c824f54a7a6a7862f8c3d0892b283"
+checksum = "446ba717509524cb3f22f17ecc096f10f4822d76ab5c0b9822c5f9c284e825f4"
 dependencies = [
  "cfg-if",
  "cpufeatures",
@@ -192,12 +197,6 @@ version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 
-[[package]]
-name = "version_check"
-version = "0.9.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
-
 [[package]]
 name = "zmij"
 version = "1.0.23"
diff --git a/conformance/mock-provider/Cargo.toml b/conformance/mock-provider/Cargo.toml
index 415b334..b02a295 100644
--- a/conformance/mock-provider/Cargo.toml
+++ b/conformance/mock-provider/Cargo.toml
@@ -9,7 +9,7 @@ publish = false
 
 [dependencies]
 lpp-conformance-common = { path = "../common" }
-sha2 = "0.10"
+sha2 = "0.11"
 serde = { workspace = true, features = ["derive"] }
 serde_json.workspace = true
 
diff --git a/conformance/mock-provider/src/methods.rs b/conformance/mock-provider/src/methods.rs
index 38d040c..8851e7f 100644
--- a/conformance/mock-provider/src/methods.rs
+++ b/conformance/mock-provider/src/methods.rs
@@ -10,6 +10,7 @@ use std::collections::HashMap;
 
 use serde_json::{Value, json};
 use sha2::{Digest, Sha256};
+use std::fmt::Write;
 
 use crate::project::documents_for_request;
 use crate::puzzle::{
@@ -436,7 +437,13 @@ fn select_artifact_format(accepted: Option<Vec<String>>) -> Result<&'static str,
 fn sha256_hex(text: &str) -> String {
     let mut hasher = Sha256::new();
     hasher.update(text.as_bytes());
-    format!("{:x}", hasher.finalize())
+    hasher
+        .finalize()
+        .iter()
+        .fold(String::new(), |mut hex, byte| {
+            write!(hex, "{byte:02x}").expect("writing to a String cannot fail");
+            hex
+        })
 }
 
 /// Document-set entries in key order.