diff --git a/CHANGELOG.md b/CHANGELOG.md
index 91c37e9..967b6e0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,8 +7,42 @@ All notable changes to this project will be documented in this file. It uses the
   [Semantic Versioning]: https://semver.org/spec/v2.0.0.html
     "Semantic Versioning 2.0.0"
 
+## [v0.4.0] — Unreleased
+
+The theme of this release is *JSON Web Signatures.*
+
+### ⚡ Improvements
+
+*   Following [RFC 5], added v2 JSON Schemas for the `certs` property and its
+    child `pgxn` property, which contains an [RFC 7515] JSON Web Signature
+    (JWS) [JSON Serialization] object in either the general or flattened
+    syntaxes.
+*   Revamped the [release module] to support the updated release signing spec
+    defined in [RFC 5]
+*   Added the `validate_payload` method to `valid::Validator`, which that the
+    `release::Release` deserialization implementation uses to validate the JWS
+    payload. Required because the payload is Base 64 URL-encoded and therefore
+    cannot be parsed into a struct on the first pass.
+
+### 📔 Notes
+
+*   The [release] interface has changed with the new data structures. The
+    [JWS-JS] data added in v0.3.0 has been replaced with [RFC 7515]-standard
+    [JSON Serialization].
+*   Upgraded to [json-patch] v3.0 and updated all other dependencies.
+
+  [v0.4.0]: https://github.com/pgxn/meta/compare/v0.3.0...v0.4.0
+  [release module]: https://docs.rs/pgxn_meta/0.4.0/pgxn_meta/release/
+  [RFC 5]: https://github.com/pgxn/rfcs/pull/5
+    "pgxn/rfs#5 Add RFC for JWS-signing PGXN releases"
+  [RFC 7515] https://datatracker.ietf.org/doc/html/rfc7515 "RFC 7515 JSON Web Signature"
+  [JSON Serialization]: https://datatracker.ietf.org/doc/html/rfc7515#section-7.2
+    "RFC 7515 JWS — JWS JSON Serialization"
+
 ## [v0.3.0] — 2024-09-23
 
+The theme of this release is *Release metadata.*
+
 ### ⚡ Improvements
 
 *   Designed experimental distribution [metadata schema] to be appended to v2
@@ -39,7 +73,7 @@ All notable changes to this project will be documented in this file. It uses the
     payload, as we are not doing any key signing, yet. For now it generates
     random strings to satisfy JSON Schema validation.
 
-  [v0.3.0]: https://github.com/pgxn/meta/compare/v0.3.0...v0.3.0
+  [v0.3.0]: https://github.com/pgxn/meta/compare/v0.2.0...v0.3.0
   [metadata schema]: https://github.com/pgxn/meta/blob/v0.3.0/schema/v2/pgxn-jws.schema.json
   [dist module]: https://docs.rs/pgxn_meta/0.3.0/pgxn_meta/dist/
   [release module]: https://docs.rs/pgxn_meta/0.3.0/pgxn_meta/release/
@@ -51,6 +85,8 @@ All notable changes to this project will be documented in this file. It uses the
 
 ## [v0.2.0] — 2024-09-12
 
+The theme of this release is *Data structures and APIs.*
+
 ### ⚡ Improvements
 
 *   Added the [meta module], which loads v1 and v2 spec files into read-only
diff --git a/Cargo.lock b/Cargo.lock
index 408d556..c1054bc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -57,9 +57,9 @@ dependencies = [
 
 [[package]]
 name = "autocfg"
-version = "1.3.0"
+version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0c4b4d0bd25bd0b74681c0ad21497610ce1b7c91b1022cd21c80c6fbdd9476b0"
+checksum = "ace50bade8e6234aa140d9a2f552bbee1db4d353f69b8217bc503490fc1a9f26"
 
 [[package]]
 name = "base64"
@@ -119,9 +119,9 @@ checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"
 
 [[package]]
 name = "cc"
-version = "1.1.19"
+version = "1.1.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2d74707dde2ba56f86ae90effb3b43ddd369504387e718014de010cec7959800"
+checksum = "2e80e3b6a3ab07840e1cae9b0666a63970dc28e8ed5ffbcdacbfc760c281bfc1"
 dependencies = [
  "shlex",
 ]
@@ -149,18 +149,18 @@ dependencies = [
 
 [[package]]
 name = "const_format"
-version = "0.2.32"
+version = "0.2.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e3a214c7af3d04997541b18d432afaff4c455e79e2029079647e72fc2bd27673"
+checksum = "50c655d81ff1114fb0dcdea9225ea9f0cc712a6f8d189378e82bdf62a473a64b"
 dependencies = [
  "const_format_proc_macros",
 ]
 
 [[package]]
 name = "const_format_proc_macros"
-version = "0.2.32"
+version = "0.2.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c7f6ff08fd20f4f299298a28e2dfa8a8ba1036e6cd2460ac1de7b425d76f2500"
+checksum = "eff1a44b93f47b1bac19a27932f5c591e43d1ba357ee4f61526c8a25603f0eb1"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -298,9 +298,9 @@ checksum = "8a9ee70c43aaf417c914396645a0fa852624801b24ebb7ae78fe8272889ac888"
 
 [[package]]
 name = "hashbrown"
-version = "0.14.5"
+version = "0.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e5274423e17b7c9fc20b6e7e208532f9b19825d82dfd615708b70edd83df41f1"
+checksum = "1e087f84d4f86bf4b218b927129862374b72199ae7d8657835f1e89000eea4fb"
 
 [[package]]
 name = "hex"
@@ -360,12 +360,12 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.5.0"
+version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "68b900aa2f7301e21c36462b170ee99994de34dff39a4a6a528e80e7376d07e5"
+checksum = "707907fe3c25f5424cce2cb7e1cbcafee6bdbe735ca90ef77c29e84591e5b9da"
 dependencies = [
  "equivalent",
- "hashbrown 0.14.5",
+ "hashbrown 0.15.0",
  "serde",
 ]
 
@@ -395,9 +395,9 @@ dependencies = [
 
 [[package]]
 name = "json-patch"
-version = "2.0.0"
+version = "3.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b1fb8864823fad91877e6caea0baca82e49e8db50f8e5c9f9a453e27d3330fc"
+checksum = "863726d7afb6bc2590eeff7135d923545e5e964f004c2ccf8716c25e70a86f08"
 dependencies = [
  "jsonptr",
  "serde",
@@ -407,11 +407,10 @@ dependencies = [
 
 [[package]]
 name = "jsonptr"
-version = "0.4.7"
+version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1c6e529149475ca0b2820835d3dce8fcc41c6b943ca608d32f35b449255e4627"
+checksum = "5dea2b27dd239b2556ed7a25ba842fe47fd602e7fc7433c2a8d6106d4d9edd70"
 dependencies = [
- "fluent-uri",
  "serde",
  "serde_json",
 ]
@@ -424,9 +423,9 @@ checksum = "baff4b617f7df3d896f97fe922b64817f6cd9a756bb81d40f8883f2f66dcb401"
 
 [[package]]
 name = "libc"
-version = "0.2.158"
+version = "0.2.159"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d8adc4bb1803a324070e64a98ae98f38934d91957a99cfb3a43dcbc01bc56439"
+checksum = "561d97a539a36e26a9a5fad1ea11a3039a67714694aaa379433e580854bc3dc5"
 
 [[package]]
 name = "linux-raw-sys"
@@ -479,9 +478,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.19.0"
+version = "1.20.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3fdb12b2476b595f9358c5161aa467c2438859caa136dec86c26fdd2efe17b92"
+checksum = "1261fe7e33c73b354eab43b1273a57c8f967d0391e80353e51f764ac02cf6775"
 
 [[package]]
 name = "percent-encoding"
@@ -491,7 +490,7 @@ checksum = "e3148f5046208a5d56bcfc03053e3ca6334e51da8dfb19b6cdc8b306fae3283e"
 
 [[package]]
 name = "pgxn_meta"
-version = "0.3.0"
+version = "0.4.0"
 dependencies = [
  "assert-json-diff",
  "base64 0.22.1",
@@ -538,18 +537,18 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.86"
+version = "1.0.87"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e719e8df665df0d1c8fbfd238015744736151d4445ec0836b8e628aae103b77"
+checksum = "b3e4daa0dcf6feba26f985457cdf104d4b4256fc5a09547140f3631bb076b19a"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.36"
+version = "1.0.37"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0fa76aaf39101c457836aec0ce2316dbdc3ab723cdda1c6bd4e6ad4208acaca7"
+checksum = "b5b9d34b8991d19d98081b46eacdd8eb58c6f2b201139f7c5f643cc155a633af"
 dependencies = [
  "proc-macro2",
 ]
@@ -586,9 +585,9 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.10.5"
+version = "1.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b91213439dad192326a0d7c6ee3955910425f441d7038e0d6933b0aec5c4517f"
+checksum = "38200e5ee88914975b69f657f0801b6f6dccafd44fd9326302a4aaeecfacb1d8"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -598,9 +597,9 @@ dependencies = [
 
 [[package]]
 name = "regex-automata"
-version = "0.4.7"
+version = "0.4.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "38caf58cc5ef2fed281f89292ef23f6365465ed9a41b7a7754eb4e26496c92df"
+checksum = "368758f23274712b504848e9d5a6f010445cc8b87a7cdb4d7cbee666c1288da3"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -609,9 +608,9 @@ dependencies = [
 
 [[package]]
 name = "regex-syntax"
-version = "0.8.4"
+version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a66a03ae7c801facd77a29370b4faec201768915ac14a721ba36f20bc9c209b"
+checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"
 
 [[package]]
 name = "relative-path"
@@ -661,18 +660,18 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.203"
+version = "1.0.210"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7253ab4de971e72fb7be983802300c30b5a7f0c2e56fab8abfc6a214307c0094"
+checksum = "c8e3592472072e6e22e0a54d5904d9febf8508f65fb8552499a1abc7d1078c3a"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.203"
+version = "1.0.210"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "500cbc0ebeb6f46627f50f3f5811ccf6bf00643be300b4c3eabc0ef55dc5b5ba"
+checksum = "243902eda00fad750862fc144cea25caca5e20d615af0a81bee94ca738f1df1f"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -681,26 +680,27 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.118"
+version = "1.0.128"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d947f6b3163d8857ea16c4fa0dd4840d52f3041039a85decd46867eb1abef2e4"
+checksum = "6ff5456707a1de34e7e37f2a6fd3d3f808c318259cbd01ab6377795054b483d8"
 dependencies = [
  "itoa",
+ "memchr",
  "ryu",
  "serde",
 ]
 
 [[package]]
 name = "serde_with"
-version = "3.9.0"
+version = "3.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "69cecfa94848272156ea67b2b1a53f20fc7bc638c4a46d2f8abde08f05f4b857"
+checksum = "8e28bdad6db2b8340e449f7108f020b3b092e8583a9e3fb82713e1d4e71fe817"
 dependencies = [
  "base64 0.22.1",
  "chrono",
  "hex",
  "indexmap 1.9.3",
- "indexmap 2.5.0",
+ "indexmap 2.6.0",
  "serde",
  "serde_derive",
  "serde_json",
@@ -710,9 +710,9 @@ dependencies = [
 
 [[package]]
 name = "serde_with_macros"
-version = "3.9.0"
+version = "3.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a8fee4991ef4f274617a51ad4af30519438dacb2f56ac773b08a1922ff743350"
+checksum = "9d846214a9854ef724f3da161b426242d8de7c1fc7de2f89bb1efcb154dca79d"
 dependencies = [
  "darling",
  "proc-macro2",
@@ -749,9 +749,9 @@ checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
 [[package]]
 name = "syn"
-version = "2.0.68"
+version = "2.0.79"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "901fa70d88b9d6c98022e23b4136f9f3e54e4662c3bc1bd1d84a42a9a0f0c1e9"
+checksum = "89132cd0bf050864e1d38dc3bbc07a0eb8e7530af26344d3d2bbbef83499f590"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -760,9 +760,9 @@ dependencies = [
 
 [[package]]
 name = "tempfile"
-version = "3.12.0"
+version = "3.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "04cbcdd0c794ebb0d4cf35e88edd2f7d2c4c3e9a5a6dab322839b321c6a87a64"
+checksum = "f0f2c9fc62d0beef6951ccffd757e241266a2c833136efbe35af6cd2567dca5b"
 dependencies = [
  "cfg-if",
  "fastrand",
@@ -773,18 +773,18 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "1.0.63"
+version = "1.0.64"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c0342370b38b6a11b6cc11d6a805569958d54cfa061a29969c3b5ce2ea405724"
+checksum = "d50af8abc119fb8bb6dbabcfa89656f46f84aa0ac7688088608076ad2b459a84"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.63"
+version = "1.0.64"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4558b58466b9ad7ca0f102865eccc95938dca1a74a856f2b57b6629050da261"
+checksum = "08904e7672f5eb876eaaf87e0ce17857500934f4981c4a0ab2b4aa98baac7fc3"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -824,9 +824,9 @@ dependencies = [
 
 [[package]]
 name = "tinyvec"
-version = "1.6.1"
+version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c55115c6fbe2d2bef26eb09ad74bde02d8255476fc0c7b515ef09fbb35742d82"
+checksum = "445e881f4f6d382d5f27c034e25eb92edd7c784ceab92a0937db7f2e9471b938"
 dependencies = [
  "tinyvec_macros",
 ]
@@ -839,30 +839,30 @@ checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
 
 [[package]]
 name = "unicode-bidi"
-version = "0.3.15"
+version = "0.3.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08f95100a766bf4f8f28f90d77e0a5461bbdb219042e7679bebe79004fed8d75"
+checksum = "5ab17db44d7388991a428b2ee655ce0c212e862eff1768a455c58f9aad6e7893"
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.12"
+version = "1.0.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3354b9ac3fae1ff6755cb6db53683adb661634f67557942dea4facebec0fee4b"
+checksum = "e91b56cd4cadaeb79bbf1a5645f6b4f8dc5bde8834ad5894a8db35fda9efa1fe"
 
 [[package]]
 name = "unicode-normalization"
-version = "0.1.23"
+version = "0.1.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a56d1686db2308d901306f92a263857ef59ea39678a5458e7cb17f01415101f5"
+checksum = "5033c97c4262335cded6d6fc3e5c18ab755e1a3dc96376350f3d8e9f009ad956"
 dependencies = [
  "tinyvec",
 ]
 
 [[package]]
 name = "unicode-xid"
-version = "0.2.4"
+version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f962df74c8c05a667b5ee8bcf162993134c104e96440b663c8daa176dc772d8c"
+checksum = "ebc1c04c71510c7f702b52b7c350734c9ff1295c464a03335b00bb84fc54f853"
 
 [[package]]
 name = "url"
@@ -877,9 +877,9 @@ dependencies = [
 
 [[package]]
 name = "version_check"
-version = "0.9.4"
+version = "0.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
+checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
 
 [[package]]
 name = "walkdir"
@@ -969,11 +969,11 @@ dependencies = [
 
 [[package]]
 name = "winapi-util"
-version = "0.1.8"
+version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4d4cc384e1e73b93bafa6fb4f1df8c41695c8a91cf9c4c64358067d15a7b6c6b"
+checksum = "cf221c93e13a30d793f7645a0e7762c55d169dbb0a49671918a2319d289b10bb"
 dependencies = [
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -1069,9 +1069,9 @@ checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
 
 [[package]]
 name = "zerocopy"
-version = "0.7.34"
+version = "0.7.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ae87e3fcd617500e5d106f0380cf7b77f3c6092aae37191433159dda23cfb087"
+checksum = "1b9b4fd18abc82b8136838da5d50bae7bdea537c574d8dc1a34ed098d6c166f0"
 dependencies = [
  "byteorder",
  "zerocopy-derive",
@@ -1079,9 +1079,9 @@ dependencies = [
 
 [[package]]
 name = "zerocopy-derive"
-version = "0.7.34"
+version = "0.7.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "15e934569e47891f7d9411f1a451d947a60e000ab3bd24fbb970f000387d1b3b"
+checksum = "fa4f8080344d4671fb4e831a13ad1e68092748387dfc4f55e356242fae12ce3e"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/Cargo.toml b/Cargo.toml
index 5cc52a4..7e88164 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "pgxn_meta"
-version = "0.3.0"
+version = "0.4.0"
 description = "The PGXN distribution metadata specification"
 repository = "https://github.com/pgxn/pgxn-meta-spec"
 documentation = "https://docs.rs/pgxn_meta/"
@@ -19,7 +19,7 @@ base64 = "0.22"
 boon = "0.6"
 chrono = { version = "0.4.38", features = ["serde"] }
 email_address = "0.2.9"
-json-patch = "2.0.0"
+json-patch = "3.0"
 lexopt = "0.3.0"
 rand = "0.8.5"
 relative-path = { version = "1.9", features = ["serde"] }