diff --git a/src/peer/identity.js b/src/peer/identity.js
index 7cb1a1d..6726fe8 100644
--- a/src/peer/identity.js
+++ b/src/peer/identity.js
@@ -1,12 +1,11 @@
 const thenifyAll = require('thenify-all')
 const path = require('path')
-const fs = thenifyAll(require('fs'), {}, ['readFile'])
+const fs = thenifyAll(require('fs'), {}, ['readFile', 'writeFile'])
 const PeerId = thenifyAll(require('peer-id'), {}, ['createFromPrivKey', 'create'])
 const PeerInfo = require('peer-info')
-const Crypto = require('libp2p-crypto')
+const Crypto = thenifyAll(require('libp2p-crypto'), {}, ['unmarshalPrivateKey'])
 const Multiaddr = require('multiaddr')
 const b58 = require('bs58')
-const { b58MultihashForBuffer } = require('../common/util')
 
 const NODE_KEY_TYPE = 'RSA'
 const NODE_KEY_BITS = 2048
@@ -129,7 +128,20 @@ function publisherKeyFromB58String (key58: string): PublicSigningKey { // eslint
 }
 
 function publisherKeyToB58String (key: PublicSigningKey): string { // eslint-disable-line no-undef
-  return b58MultihashForBuffer(key.bytes)
+  return b58.encode(key.bytes)
+}
+
+function loadPublisherId (filename: string): Promise<PublisherId> {
+  return fs.readFile(filename)
+    .then(bytes => Crypto.unmarshalPrivateKey(bytes))
+    .then(privateKey => ({
+      id58: b58.encode(privateKey.public.bytes),
+      privateKey
+    }))
+}
+
+function savePublisherId (publisherId: PublisherId, filename: string): Promise<void> {
+  return fs.writeFile(filename, publisherId.privateKey.bytes)
 }
 
 function signBuffer (
@@ -164,6 +176,8 @@ module.exports = {
   loadOrGenerateIdentity,
   inflateMultiaddr,
   generatePublisherId,
+  loadPublisherId,
+  savePublisherId,
   publisherKeyFromB58String,
   publisherKeyToB58String,
   signBuffer,
diff --git a/test/resources/generate_test_publisher_ids.js b/test/resources/generate_test_publisher_ids.js
new file mode 100644
index 0000000..c4ff2d9
--- /dev/null
+++ b/test/resources/generate_test_publisher_ids.js
@@ -0,0 +1,19 @@
+const path = require('path')
+const mkdirp = require('mkdirp')
+const {generatePublisherId, savePublisherId} = require('../../lib/peer/identity')
+
+const NUM_IDS = 20
+const outputDir = path.join(__dirname, 'publisher_ids')
+mkdirp.sync(outputDir)
+
+const promises = []
+for (let i = 0; i < NUM_IDS; i++) {
+  promises.push(
+    generatePublisherId().then(id =>
+      savePublisherId(id, path.join(outputDir, `${id.id58}.id`)))
+  )
+}
+
+Promise.all(promises).then(ids => {
+  console.log(`wrote ${ids.length} ids to ${outputDir}`)
+})
diff --git a/test/resources/publisher_ids/4XTTM2UhNoDF1EfwonksnNN1zRGcZCMFutDRMtXYgciwiLzCf.id b/test/resources/publisher_ids/4XTTM2UhNoDF1EfwonksnNN1zRGcZCMFutDRMtXYgciwiLzCf.id
new file mode 100644
index 0000000..852abd5
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTM2UhNoDF1EfwonksnNN1zRGcZCMFutDRMtXYgciwiLzCf.id
@@ -0,0 +1 @@
+
`���\t�N���ia�ɥ6u&"��ӿ����E*�/�}������*#�W�؊���(��բ4��/�}������*#�W�؊���(��բ4�
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTM33j1mHcbg5ctzCmsmvaiUCixX5jxTbkKHm2vCokC6uxw.id b/test/resources/publisher_ids/4XTTM33j1mHcbg5ctzCmsmvaiUCixX5jxTbkKHm2vCokC6uxw.id
new file mode 100644
index 0000000..4675604
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTM33j1mHcbg5ctzCmsmvaiUCixX5jxTbkKHm2vCokC6uxw.id
@@ -0,0 +1 @@
+
`�4̌6�F���E���Q��K���X+_��O�'m�Z4I�����7}:�9�%��'��Y^�>�>TZ4I�����7}:�9�%��'��Y^�>�>T
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTM3NVNm4VryWP91VXdEeoDXC2NzZkKRvUmPMnb1JdosJFk.id b/test/resources/publisher_ids/4XTTM3NVNm4VryWP91VXdEeoDXC2NzZkKRvUmPMnb1JdosJFk.id
new file mode 100644
index 0000000..30989c5
Binary files /dev/null and b/test/resources/publisher_ids/4XTTM3NVNm4VryWP91VXdEeoDXC2NzZkKRvUmPMnb1JdosJFk.id differ
diff --git a/test/resources/publisher_ids/4XTTM6UEBfKSWUnC4KERbW8hesAAAGgrZcu68AXqihsFvU8w6.id b/test/resources/publisher_ids/4XTTM6UEBfKSWUnC4KERbW8hesAAAGgrZcu68AXqihsFvU8w6.id
new file mode 100644
index 0000000..4a609fc
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTM6UEBfKSWUnC4KERbW8hesAAAGgrZcu68AXqihsFvU8w6.id
@@ -0,0 +1 @@
+
`�-N����xV�څ��]�N�lSP]u��]�F'xO40r��e��v�Ìw*���A7;�YO40r��e��v�Ìw*���A7;�Y
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTM6UNDgjn7Y6FqnGyKiRf7NmqKzi7ofeh3ZRzFGmv5tkyQ.id b/test/resources/publisher_ids/4XTTM6UNDgjn7Y6FqnGyKiRf7NmqKzi7ofeh3ZRzFGmv5tkyQ.id
new file mode 100644
index 0000000..a4f0ecc
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTM6UNDgjn7Y6FqnGyKiRf7NmqKzi7ofeh3ZRzFGmv5tkyQ.id
@@ -0,0 +1 @@
+
`�`�Q8➭��)�^=ˢ��Yh�d��[ф`��O=E���JL�4��­�,^3P��K��겑�.�O=E���JL�4��­�,^3P��K��겑�.�
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTM7xSyXgsrwG83aXEKt5Edp9LFmqxCxum1ABXAXDw5QHHy.id b/test/resources/publisher_ids/4XTTM7xSyXgsrwG83aXEKt5Edp9LFmqxCxum1ABXAXDw5QHHy.id
new file mode 100644
index 0000000..caa342b
Binary files /dev/null and b/test/resources/publisher_ids/4XTTM7xSyXgsrwG83aXEKt5Edp9LFmqxCxum1ABXAXDw5QHHy.id differ
diff --git a/test/resources/publisher_ids/4XTTMATDw8fXWT5BGGaoc4A2sEbnLmMYBbekYnznDJ9K8c2cg.id b/test/resources/publisher_ids/4XTTMATDw8fXWT5BGGaoc4A2sEbnLmMYBbekYnznDJ9K8c2cg.id
new file mode 100644
index 0000000..e228b4f
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTMATDw8fXWT5BGGaoc4A2sEbnLmMYBbekYnznDJ9K8c2cg.id
@@ -0,0 +1,2 @@
+
`������4�s����G����
+�3<�Z��rٌ �aJ�H�ɦge���qkZ�y��6��F>R��aJ�H�ɦge���qkZ�y��6��F>R��
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTMAhtTw2zgTVa5XFxHKeXcJGftdCVmsGR5zYzGspdLr2qf.id b/test/resources/publisher_ids/4XTTMAhtTw2zgTVa5XFxHKeXcJGftdCVmsGR5zYzGspdLr2qf.id
new file mode 100644
index 0000000..e40527a
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTMAhtTw2zgTVa5XFxHKeXcJGftdCVmsGR5zYzGspdLr2qf.id
@@ -0,0 +1 @@
+
`�Ibe� �(.�3md>=�u�?�7H��5��Î"������@^�7�$YB`�ъA�.z~B�"������@^�7�$YB`�ъA�.z~B
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTMB2cFTq23PTFGEdeT93cLdNptcSUekShxoUp5vzkjbkA4.id b/test/resources/publisher_ids/4XTTMB2cFTq23PTFGEdeT93cLdNptcSUekShxoUp5vzkjbkA4.id
new file mode 100644
index 0000000..8c05688
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTMB2cFTq23PTFGEdeT93cLdNptcSUekShxoUp5vzkjbkA4.id
@@ -0,0 +1,2 @@
+
`�
+�E��ZΦ
,t!M�j��h��B#���ג�x�f�Z`��]�� ���	 ~궱�ML=���x�f�Z`��]�� ���	 ~궱�ML=�
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTMBauYYKRkmWLyDwdU2sb4JgQX7VoZwwkPpmeFqrQoWWt7.id b/test/resources/publisher_ids/4XTTMBauYYKRkmWLyDwdU2sb4JgQX7VoZwwkPpmeFqrQoWWt7.id
new file mode 100644
index 0000000..3444771
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTMBauYYKRkmWLyDwdU2sb4JgQX7VoZwwkPpmeFqrQoWWt7.id
@@ -0,0 +1 @@
+
`��f��|��S5�rB���	֮I�s�Qs4�Gm��4��)?�[���shN8�CuB����a��˰�4��)?�[���shN8�CuB����a��˰
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTMCh4xe8E49486DUFko3cmqak3vrymKd5kMUBAVhMbxUkj.id b/test/resources/publisher_ids/4XTTMCh4xe8E49486DUFko3cmqak3vrymKd5kMUBAVhMbxUkj.id
new file mode 100644
index 0000000..cd16780
Binary files /dev/null and b/test/resources/publisher_ids/4XTTMCh4xe8E49486DUFko3cmqak3vrymKd5kMUBAVhMbxUkj.id differ
diff --git a/test/resources/publisher_ids/4XTTMDi5msCJgo8GFAHvZkE57cCK4QCPRQSrUSQcPMqQexT3E.id b/test/resources/publisher_ids/4XTTMDi5msCJgo8GFAHvZkE57cCK4QCPRQSrUSQcPMqQexT3E.id
new file mode 100644
index 0000000..3bdfe1c
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTMDi5msCJgo8GFAHvZkE57cCK4QCPRQSrUSQcPMqQexT3E.id
@@ -0,0 +1 @@
+
`Iu^�
���L
���Ly�g�9�O�܋ݹ'�ž;��
vv�-VI�Z��8=�g��T��읟q�ž;��
vv�-VI�Z��8=�g��T��읟q
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTMEj74YR3oT18Uh1ZR1DbWpG5BXftvcSnyrwC6JbgS9AcG.id b/test/resources/publisher_ids/4XTTMEj74YR3oT18Uh1ZR1DbWpG5BXftvcSnyrwC6JbgS9AcG.id
new file mode 100644
index 0000000..c93fad0
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTMEj74YR3oT18Uh1ZR1DbWpG5BXftvcSnyrwC6JbgS9AcG.id
@@ -0,0 +1 @@
+
`�(F�Ҋ�Ď�P��m�Ft�
���aa�m+@���Wt��#�7�ͽ��e�`�A�u��Y����q��Wt��#�7�ͽ��e�`�A�u��Y����q
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTMF7HGrVmmnFATLrCMwboCDxnnm6CPcC8dyE8Tigfb5kYh.id b/test/resources/publisher_ids/4XTTMF7HGrVmmnFATLrCMwboCDxnnm6CPcC8dyE8Tigfb5kYh.id
new file mode 100644
index 0000000..532391b
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTMF7HGrVmmnFATLrCMwboCDxnnm6CPcC8dyE8Tigfb5kYh.id
@@ -0,0 +1,2 @@
+
`/��r�l�	�4
+!���fU7���@�@��>�EϏ��s�W�Ȝ����=��u�m��n�'��Ϗ��s�W�Ȝ����=��u�m��n�'��
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTMFB2m8B8ShvUiXNuywUmK6r3e8YM5fsQsLArHMeUpjhWk.id b/test/resources/publisher_ids/4XTTMFB2m8B8ShvUiXNuywUmK6r3e8YM5fsQsLArHMeUpjhWk.id
new file mode 100644
index 0000000..db205ee
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTMFB2m8B8ShvUiXNuywUmK6r3e8YM5fsQsLArHMeUpjhWk.id
@@ -0,0 +1,3 @@
+
`l[Ǵ��r;P��۱	��U���~�(z�#��Ѕ����;��-��
+�4.��(��KNЮ����Ѕ����;��-��
+�4.��(��KN����
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTMFSVc6B4fRt5s71438dXcPE9NBPVQ5sRow1qtcARARHCJ.id b/test/resources/publisher_ids/4XTTMFSVc6B4fRt5s71438dXcPE9NBPVQ5sRow1qtcARARHCJ.id
new file mode 100644
index 0000000..8138e82
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTMFSVc6B4fRt5s71438dXcPE9NBPVQ5sRow1qtcARARHCJ.id
@@ -0,0 +1,2 @@
+
`%A�x�.��E�d�Aܴ�L���F��
+�O'�{�2 �1��z|��J/
��&.D�H���F6���{�2 �1��z|��J/
��&.D�H���F6��
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTMFVjr2Zga6A1PF4GPZ43fSqvgWUfR8T3seEsfEBe3PUDi.id b/test/resources/publisher_ids/4XTTMFVjr2Zga6A1PF4GPZ43fSqvgWUfR8T3seEsfEBe3PUDi.id
new file mode 100644
index 0000000..b879e96
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTMFVjr2Zga6A1PF4GPZ43fSqvgWUfR8T3seEsfEBe3PUDi.id
@@ -0,0 +1,3 @@
+
`�q� ��:���ŢS�k�܍����^����7��P}B	<���ٜ�K����l"��1A�
+�\]�P}B	<���ٜ�K����l"��1A�
+�\]
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTMGbTZFhxPnpwUmC8JaQS6NHeLj98TdbdjSeAT9qupk5x9.id b/test/resources/publisher_ids/4XTTMGbTZFhxPnpwUmC8JaQS6NHeLj98TdbdjSeAT9qupk5x9.id
new file mode 100644
index 0000000..5196566
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTMGbTZFhxPnpwUmC8JaQS6NHeLj98TdbdjSeAT9qupk5x9.id
@@ -0,0 +1 @@
+
`zF������mWS�0�$�F���� 
�>)�A�>)6��/@D����U���3&WZa�OP6�>)6��/@D����U���3&WZa�OP6
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTMHa54HQoW8Lp6nLUzKt5QwZAUxux6DDshbBN5w4WNj759.id b/test/resources/publisher_ids/4XTTMHa54HQoW8Lp6nLUzKt5QwZAUxux6DDshbBN5w4WNj759.id
new file mode 100644
index 0000000..088f40a
--- /dev/null
+++ b/test/resources/publisher_ids/4XTTMHa54HQoW8Lp6nLUzKt5QwZAUxux6DDshbBN5w4WNj759.id
@@ -0,0 +1 @@
+
`v�`���o@�1�@�C5"�]�{ؤ�|̃�#���Dh���8��ʨ•�Y���}+6�_��#���Dh���8��ʨ•�Y���}+6�_�
\ No newline at end of file
diff --git a/test/resources/publisher_ids/4XTTMHhM2e1nPVRgN6M7WM8WUcCnVwYwb8aS3ou9uKg5rdrHX.id b/test/resources/publisher_ids/4XTTMHhM2e1nPVRgN6M7WM8WUcCnVwYwb8aS3ou9uKg5rdrHX.id
new file mode 100644
index 0000000..eb0bf39
Binary files /dev/null and b/test/resources/publisher_ids/4XTTMHhM2e1nPVRgN6M7WM8WUcCnVwYwb8aS3ou9uKg5rdrHX.id differ