diff --git a/contrib/backends/bcash/Makefile b/contrib/backends/bcash/Makefile
index b42666cf..dc8cc34d 100644
--- a/contrib/backends/bcash/Makefile
+++ b/contrib/backends/bcash/Makefile
@@ -1,12 +1,15 @@
 BITCOINABC_VERSION := 0.17.1
+BITCOINABC_ARCHIVE := bitcoin-abc-${BITCOINABC_VERSION}-x86_64-linux-gnu.tar.gz
+BITCOINABC_SHA256 := eccf8b61ba0549f6839e586c7dc6fc4bf6d7591ac432aaea8a7df0266b113d27
 
 all:
-	wget https://download.bitcoinabc.org/${BITCOINABC_VERSION}/linux/bitcoin-abc-${BITCOINABC_VERSION}-x86_64-linux-gnu.tar.gz
-	tar -xf bitcoin-abc-${BITCOINABC_VERSION}-x86_64-linux-gnu.tar.gz
+	wget https://download.bitcoinabc.org/${BITCOINABC_VERSION}/linux/${BITCOINABC_ARCHIVE}
+	[ "$$(sha256sum ${BITCOINABC_ARCHIVE} | cut -d ' ' -f 1)" = "${BITCOINABC_SHA256}" ]
+	tar -xf ${BITCOINABC_ARCHIVE}
 	mv bitcoin-abc-${BITCOINABC_VERSION} bitcoin-abc
 	rm bitcoin-abc/bin/bitcoin-qt
 	rm bitcoin-abc/bin/test_bitcoin
 
 clean:
 	rm -rf bitcoin-abc
-	rm -f bitcoin-abc-${BITCOINABC_VERSION}-x86_64-linux-gnu.tar.gz*
+	rm -f ${BITCOINABC_ARCHIVE}*
diff --git a/contrib/backends/bgold/Makefile b/contrib/backends/bgold/Makefile
index e72f706a..e566b149 100644
--- a/contrib/backends/bgold/Makefile
+++ b/contrib/backends/bgold/Makefile
@@ -1,13 +1,18 @@
 BGOLD_VERSION := 0.15.1
-BUILD_VERSION := 
+BUILD_VERSION :=
+BGOLD_ARCHIVE := bitcoin-gold-${BGOLD_VERSION}-x86_64-linux-gnu.tar.gz
 
 all:
-	wget https://github.com/BTCGPU/BTCGPU/releases/download/v${BGOLD_VERSION}${BUILD_VERSION}/bitcoin-gold-${BGOLD_VERSION}-x86_64-linux-gnu.tar.gz
-	tar -xf bitcoin-gold-${BGOLD_VERSION}-x86_64-linux-gnu.tar.gz
+	wget https://github.com/BTCGPU/BTCGPU/releases/download/v${BGOLD_VERSION}${BUILD_VERSION}/${BGOLD_ARCHIVE}
+	wget https://github.com/BTCGPU/BTCGPU/releases/download/v${BGOLD_VERSION}/SHA256SUMS.asc
+	gpg --verify SHA256SUMS.asc
+	sha256sum -c --ignore-missing SHA256SUMS.asc
+	tar -xf ${BGOLD_ARCHIVE}
 	mv bitcoin-gold-${BGOLD_VERSION} bgold
 	rm bgold/bin/bitcoin-qt
 	rm bgold/bin/test_bitcoin
 
 clean:
 	rm -rf bgold
-	rm -f bitcoin-gold-${BGOLD_VERSION}-x86_64-linux-gnu.tar.gz*
+	rm -f ${BGOLD_ARCHIVE}
+	rm -f SHA256SUMS.asc
diff --git a/contrib/backends/bitcoin/Makefile b/contrib/backends/bitcoin/Makefile
index 2ccdffde..7a30eb33 100644
--- a/contrib/backends/bitcoin/Makefile
+++ b/contrib/backends/bitcoin/Makefile
@@ -1,12 +1,17 @@
 BITCOIN_VERSION := 0.16.1
+BITCOIN_ARCHIVE := bitcoin-${BITCOIN_VERSION}-x86_64-linux-gnu.tar.gz
 
 all:
-	wget https://bitcoin.org/bin/bitcoin-core-${BITCOIN_VERSION}/bitcoin-${BITCOIN_VERSION}-x86_64-linux-gnu.tar.gz
-	tar -xf bitcoin-${BITCOIN_VERSION}-x86_64-linux-gnu.tar.gz
+	wget https://bitcoin.org/bin/bitcoin-core-${BITCOIN_VERSION}/${BITCOIN_ARCHIVE}
+	wget https://bitcoin.org/bin/bitcoin-core-${BITCOIN_VERSION}/SHA256SUMS.asc
+	gpg --verify SHA256SUMS.asc
+	sha256sum -c --ignore-missing SHA256SUMS.asc
+	tar -xf ${BITCOIN_ARCHIVE}
 	mv bitcoin-${BITCOIN_VERSION} bitcoin
 	rm bitcoin/bin/bitcoin-qt
 	rm bitcoin/bin/test_bitcoin
 
 clean:
 	rm -rf bitcoin
-	rm -f bitcoin-${BITCOIN_VERSION}-x86_64-linux-gnu.tar.gz*
+	rm -f ${BITCOIN_ARCHIVE}
+	rm -f SHA256SUMS.asc
diff --git a/contrib/backends/dash/Makefile b/contrib/backends/dash/Makefile
index c4364c36..17cb709a 100644
--- a/contrib/backends/dash/Makefile
+++ b/contrib/backends/dash/Makefile
@@ -1,9 +1,13 @@
 DASH_VERSION := 0.12.3
 DASH_BUILD := .2
+DASH_ARCHIVE := dashcore-${DASH_VERSION}${DASH_BUILD}-x86_64-linux-gnu.tar.gz
 
 all:
-	wget https://github.com/dashpay/dash/releases/download/v${DASH_VERSION}${DASH_BUILD}/dashcore-${DASH_VERSION}${DASH_BUILD}-x86_64-linux-gnu.tar.gz
-	tar -xf dashcore-${DASH_VERSION}${DASH_BUILD}-x86_64-linux-gnu.tar.gz
+	wget https://github.com/dashpay/dash/releases/download/v${DASH_VERSION}${DASH_BUILD}/${DASH_ARCHIVE}
+	wget https://github.com/dashpay/dash/releases/download/v${DASH_VERSION}${DASH_BUILD}/SHA256SUMS.asc
+	gpg --verify SHA256SUMS.asc
+	sha256sum -c --ignore-missing SHA256SUMS.asc
+	tar -xf ${DASH_ARCHIVE}
 	mv dashcore-${DASH_VERSION} dash
 	rm dash/bin/dash-qt
 	rm dash/bin/test_dash
@@ -11,4 +15,5 @@ all:
 
 clean:
 	rm -rf dash
-	rm -f dashcore-${DASH_VERSION}${DASH_BUILD}-x86_64-linux-gnu.tar.gz
+	rm -f ${DASH_ARCHIVE}
+	rm -f SHA256SUMS.asc
diff --git a/contrib/backends/docker/Dockerfile b/contrib/backends/docker/Dockerfile
index 75e94805..95daed38 100644
--- a/contrib/backends/docker/Dockerfile
+++ b/contrib/backends/docker/Dockerfile
@@ -8,6 +8,9 @@ RUN apt-get update && \
 
 ADD build.sh /deb/build.sh
 
+ADD gpg-keys /tmp/gpg-keys
+RUN gpg --import /tmp/gpg-keys/*
+
 WORKDIR /deb
 
 ENTRYPOINT ["/deb/build.sh"]
diff --git a/contrib/backends/docker/gpg-keys/bgold-releases.asc b/contrib/backends/docker/gpg-keys/bgold-releases.asc
new file mode 100644
index 00000000..611aa642
--- /dev/null
+++ b/contrib/backends/docker/gpg-keys/bgold-releases.asc
@@ -0,0 +1,48 @@
+-----BEGIN PGP PUBLIC KEY BLOCK-----
+Version: SKS 1.1.6
+Comment: Hostname: keys2.kfwebs.net
+
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+-----END PGP PUBLIC KEY BLOCK-----
diff --git a/contrib/backends/docker/gpg-keys/bitcoin-releases.asc b/contrib/backends/docker/gpg-keys/bitcoin-releases.asc
new file mode 100644
index 00000000..69fc13e8
--- /dev/null
+++ b/contrib/backends/docker/gpg-keys/bitcoin-releases.asc
@@ -0,0 +1,280 @@
+-----BEGIN PGP PUBLIC KEY BLOCK-----
+Version: GnuPG v1
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+-----END PGP PUBLIC KEY BLOCK-----
diff --git a/contrib/backends/docker/gpg-keys/dash-releases.asc b/contrib/backends/docker/gpg-keys/dash-releases.asc
new file mode 100644
index 00000000..3a1fdbd4
--- /dev/null
+++ b/contrib/backends/docker/gpg-keys/dash-releases.asc
@@ -0,0 +1,52 @@
+-----BEGIN PGP PUBLIC KEY BLOCK-----
+Comment: GPGTools - https://gpgtools.org
+
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+-----END PGP PUBLIC KEY BLOCK-----
diff --git a/contrib/backends/docker/gpg-keys/eth-releases.asc b/contrib/backends/docker/gpg-keys/eth-releases.asc
new file mode 100644
index 00000000..de73f7b9
--- /dev/null
+++ b/contrib/backends/docker/gpg-keys/eth-releases.asc
@@ -0,0 +1,35 @@
+-----BEGIN PGP PUBLIC KEY BLOCK-----
+Version: SKS 1.1.6
+Comment: Hostname: keyserver.ubuntu.com
+
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+-----END PGP PUBLIC KEY BLOCK-----
diff --git a/contrib/backends/docker/gpg-keys/litecoin-releases.asc b/contrib/backends/docker/gpg-keys/litecoin-releases.asc
new file mode 100644
index 00000000..5a7c1c1d
--- /dev/null
+++ b/contrib/backends/docker/gpg-keys/litecoin-releases.asc
@@ -0,0 +1,113 @@
+-----BEGIN PGP PUBLIC KEY BLOCK-----
+Version: SKS 1.1.6
+Comment: Hostname: pgp.mit.edu
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+=OrL4
+-----END PGP PUBLIC KEY BLOCK-----
diff --git a/contrib/backends/docker/gpg-keys/vertcoin-releases.asc b/contrib/backends/docker/gpg-keys/vertcoin-releases.asc
new file mode 100644
index 00000000..08f37faa
--- /dev/null
+++ b/contrib/backends/docker/gpg-keys/vertcoin-releases.asc
@@ -0,0 +1,28 @@
+-----BEGIN PGP PUBLIC KEY BLOCK-----
+Version: SKS 1.1.6
+Comment: Hostname: pgp.mit.edu
+
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+=tN19
+-----END PGP PUBLIC KEY BLOCK-----
diff --git a/contrib/backends/docker/gpg-keys/zcash-releases.asc b/contrib/backends/docker/gpg-keys/zcash-releases.asc
new file mode 100644
index 00000000..f59d3bf1
--- /dev/null
+++ b/contrib/backends/docker/gpg-keys/zcash-releases.asc
@@ -0,0 +1,28 @@
+-----BEGIN PGP PUBLIC KEY BLOCK-----
+
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+=YKuG
+-----END PGP PUBLIC KEY BLOCK-----
diff --git a/contrib/backends/dogecoin/Makefile b/contrib/backends/dogecoin/Makefile
index 65f4bb29..0da62d68 100644
--- a/contrib/backends/dogecoin/Makefile
+++ b/contrib/backends/dogecoin/Makefile
@@ -1,8 +1,11 @@
 DOGECOIN_VERSION := 1.10.0
+DOGECOIN_ARCHIVE := dogecoin-${DOGECOIN_VERSION}-linux64.tar.gz
+DOGECOIN_SHA256 := 2e5b61842695d74ebcd30f21014cf74b6265f0f7756e9f140f031259bb3cd656
 
 all:
-	wget https://github.com/dogecoin/dogecoin/releases/download/v${DOGECOIN_VERSION}/dogecoin-${DOGECOIN_VERSION}-linux64.tar.gz
-	tar -xf dogecoin-${DOGECOIN_VERSION}-linux64.tar.gz
+	wget https://github.com/dogecoin/dogecoin/releases/download/v${DOGECOIN_VERSION}/${DOGECOIN_ARCHIVE}
+	[ "$$(sha256sum ${DOGECOIN_ARCHIVE} | cut -d ' ' -f 1)" = "${DOGECOIN_SHA256}" ]
+	tar -xf ${DOGECOIN_ARCHIVE}
 	mv dogecoin-${DOGECOIN_VERSION} dogecoin
 	rm dogecoin/bin/dogecoin-qt
 	rm dogecoin/bin/test_dogecoin*
@@ -10,4 +13,4 @@ all:
 
 clean:
 	rm -rf dogecoin
-	rm -f dogecoin-${DOGECOIN_VERSION}-linux64.tar.gz
+	rm -f ${DOGECOIN_ARCHIVE}
diff --git a/contrib/backends/ethereum/Makefile b/contrib/backends/ethereum/Makefile
index a7a73b56..62d0b89b 100644
--- a/contrib/backends/ethereum/Makefile
+++ b/contrib/backends/ethereum/Makefile
@@ -2,9 +2,12 @@ GETH_VERSION := 1.8.10-eae63c51
 
 all:
 	wget https://gethstore.blob.core.windows.net/builds/geth-linux-amd64-${GETH_VERSION}.tar.gz
+	wget https://gethstore.blob.core.windows.net/builds/geth-linux-amd64-${GETH_VERSION}.tar.gz.asc
+	gpg --verify geth-linux-amd64-${GETH_VERSION}.tar.gz.asc
 	tar -xf geth-linux-amd64-${GETH_VERSION}.tar.gz
 	mv geth-linux-amd64-${GETH_VERSION} ethereum
 
 clean:
 	rm -rf ethereum
-	rm -f geth-linux-amd64-${GETH_VERSION}.tar.gz*
+	rm -f geth-linux-amd64-${GETH_VERSION}.tar.gz
+	rm -f geth-linux-amd64-${GETH_VERSION}.tar.gz.asc
diff --git a/contrib/backends/litecoin/Makefile b/contrib/backends/litecoin/Makefile
index 3df13fbb..77a0902a 100644
--- a/contrib/backends/litecoin/Makefile
+++ b/contrib/backends/litecoin/Makefile
@@ -2,6 +2,9 @@ LITECOIN_VERSION := 0.16.0
 
 all:
 	wget https://download.litecoin.org/litecoin-${LITECOIN_VERSION}/linux/litecoin-${LITECOIN_VERSION}-x86_64-linux-gnu.tar.gz
+	wget https://download.litecoin.org/litecoin-${LITECOIN_VERSION}/linux/litecoin-${LITECOIN_VERSION}-linux-signatures.asc
+	gpg --verify litecoin-${LITECOIN_VERSION}-linux-signatures.asc
+	sha256sum -c --ignore-missing litecoin-${LITECOIN_VERSION}-linux-signatures.asc
 	tar -xf litecoin-${LITECOIN_VERSION}-x86_64-linux-gnu.tar.gz
 	mv litecoin-${LITECOIN_VERSION} litecoin
 	rm litecoin/bin/litecoin-qt
@@ -11,3 +14,4 @@ all:
 clean:
 	rm -rf litecoin
 	rm -f litecoin-${LITECOIN_VERSION}-x86_64-linux-gnu.tar.gz
+	rm -f litecoin-${LITECOIN_VERSION}-linux-signatures.asc
diff --git a/contrib/backends/namecoin/Makefile b/contrib/backends/namecoin/Makefile
index 5b5d7498..d9c40e42 100644
--- a/contrib/backends/namecoin/Makefile
+++ b/contrib/backends/namecoin/Makefile
@@ -1,8 +1,11 @@
 NAMECOIN_VERSION := 0.13.99
+NAMECOIN_ARCHIVE := namecoin-${NAMECOIN_VERSION}-x86_64-linux-gnu.tar.gz
+NAMECOIN_SHA256 := 294b1106001d6ea2b9d9ee6a655021ef207a24e8f1dec8efd5899728b3849129
 
 all:
-	wget https://namecoin.org/files/namecoin-core-${NAMECOIN_VERSION}-name-tab-beta1-notreproduced/namecoin-${NAMECOIN_VERSION}-x86_64-linux-gnu.tar.gz
-	tar -xf namecoin-${NAMECOIN_VERSION}-x86_64-linux-gnu.tar.gz
+	wget https://namecoin.org/files/namecoin-core-${NAMECOIN_VERSION}-name-tab-beta1-notreproduced/${NAMECOIN_ARCHIVE}
+	[ "$$(sha256sum ${NAMECOIN_ARCHIVE} | cut -d ' ' -f 1)" = "${NAMECOIN_SHA256}" ]
+	tar -xf ${NAMECOIN_ARCHIVE}
 	mv namecoin-${NAMECOIN_VERSION} namecoin
 	rm namecoin/bin/namecoin-qt
 	rm namecoin/bin/test_namecoin*
@@ -10,4 +13,4 @@ all:
 
 clean:
 	rm -rf namecoin
-	rm -f namecoin-${NAMECOIN_VERSION}-x86_64-linux-gnu.tar.gz
+	rm -f ${NAMECOIN_ARCHIVE}
diff --git a/contrib/backends/vertcoin/Makefile b/contrib/backends/vertcoin/Makefile
index ad6c3121..a65730b9 100644
--- a/contrib/backends/vertcoin/Makefile
+++ b/contrib/backends/vertcoin/Makefile
@@ -2,9 +2,12 @@ VERTCOIN_VERSION := 0.13.2
 
 all:
 	wget https://github.com/vertcoin-project/vertcoin-core/releases/download/${VERTCOIN_VERSION}/vertcoind-v${VERTCOIN_VERSION}-linux-amd64.zip
+	wget https://github.com/vertcoin-project/vertcoin-core/releases/download/${VERTCOIN_VERSION}/vertcoind-v${VERTCOIN_VERSION}-linux-amd64.zip.sig
+	gpg --verify vertcoind-v${VERTCOIN_VERSION}-linux-amd64.zip.sig
 	mkdir vertcoin
 	unzip vertcoind-v${VERTCOIN_VERSION}-linux-amd64.zip -d vertcoin/
 
 clean:
 	rm -rf vertcoin
 	rm -f vertcoind-v${VERTCOIN_VERSION}-linux-amd64.zip
+	rm -f vertcoind-v${VERTCOIN_VERSION}-linux-amd64.zip.sig
diff --git a/contrib/backends/zcash/Makefile b/contrib/backends/zcash/Makefile
index d4caf2b8..32b0198d 100644
--- a/contrib/backends/zcash/Makefile
+++ b/contrib/backends/zcash/Makefile
@@ -1,10 +1,14 @@
 ZCASH_VERSION := 1.1.1
+ZCASH_ARCHIVE := zcash-${ZCASH_VERSION}-linux64.tar.gz
 
 all:
-	wget https://z.cash/downloads/zcash-${ZCASH_VERSION}-linux64.tar.gz
-	tar -xf zcash-${ZCASH_VERSION}-linux64.tar.gz
+	wget https://z.cash/downloads/${ZCASH_ARCHIVE}
+	wget https://z.cash/downloads/${ZCASH_ARCHIVE}.asc
+	gpg --verify ${ZCASH_ARCHIVE}.asc
+	tar -xf ${ZCASH_ARCHIVE}
 	mv zcash-${ZCASH_VERSION} zcash
 
 clean:
 	rm -rf zcash
-	rm -f zcash-${ZCASH_VERSION}-linux64.tar.gz*
+	rm -f ${ZCASH_ARCHIVE}
+	rm -f ${ZCASH_ARCHIVE}.asc