Whether you need to #WorkFromHome due to the recent #CoronaVirus health warnings, or you #telecommute regularly, you can find a secure alternative to Slack within this list of private communications and collaboration software leaders.

1. Secure Communication &
Collaboration Software
Comparison
2019 by Mill Montejo

2. Side by Side Comparison
JobSearchSuperhero.com
2019 Research
Semaphor
Slack-ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
Bottomline
comments
A bit expensive
for small
businesses
Requires hosting Requires hosting No hosting required Encrypted chat
End to End
Encrypted chat,
phone calls, can
create group chats,
offers stickers
Private domain via
Siteground or
ProtonMail Pro
Host your own Linux
server
Questions
1. Will they
charge to add
new users?
2. Is there a cap
on users?
3. Do they permit
importing data
from Slack?
4. Could they sell
the company to
Slack or another
corporation?
1. Will they charge
to add new users?
2. Is there a cap on
users?
3. Do they permit
importing data from
Slack?
4. Could they sell
the company to
Slack or another
corporation?
1. Will they charge
to add new users?
2. Is there a cap on
users?
3. Do they permit
importing data from
Slack?
4. Could they sell
the company to
Slack or another
corporation?
1. Will they charge
to add new users?
2. Is there a cap on
users?
3. Do they permit
importing data from
Slack?
4. Could they sell
the company to
Slack or another
corporation?
1. Will they charge
to add new users?
2. Is there a cap on
users?
3. Do they permit
importing data from
Slack?
4. Could they sell
the company to
Slack or another
corporation?
1. Will they charge
to add new users?
2. Is there a cap on
users?
3. Do they permit
importing data from
Slack?
4. Could they sell
the company to
Slack or another
corporation?
1. Will they charge
to add new users?
2. Is there a cap on
users?
3. Do they permit
importing data from
Slack?
4. Could they sell
the company to
Slack or another
corporation?
Private server
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Computer Wiz
2

3. JobSearchSuperhero.com
2019 Research
Semaphor
Slack-ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
Hosting
Semaphor is
built on a core of
end-to-end
encrypted, No
Knowledge
technology in
SpiderOak's
confidential
cloud
Mattermost is only
available as an on-
premise, open
source solution.
Mattermost
requires
organizations to
purchase hardware
that match their
specifications, self-
install the software,
and administrate
the software which
can end up being
more costly for an
organization in time
and money.
Private independent
hosting, seperately
arranged
open source
powered by public
key cryptography
cloud based &
enterprise self
hosting solutions
available
n/a
encrypted mail
hosting; no logging
of IP addresses,
and all your emails
are end-to-end
encrypted, which
means there's no
way ProtonMail (or
anyone else) can
read their contents
Private server
HOSTING
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Computer Wiz
3

4. JobSearchSuperhero.c
om 2019 Research
Semaphor Slack-
ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
Platform cost
5 free users then
$10 per month per
additional user. 25%
DISCOUNT FOR
NON-PROFITS so
$7.50 per user per
month beyond the
first 5. SpiderOak
hosts Semaphor in
our confidential
cloud environment.
This allows your
organization to save
money on
hardware, IT
administration
costs, and time that
would be spent on
creating and
maintaining a self-
hosted environment.
$100 per month via
private hosting .
Mattermost is only
available as a self-
hosted product.
Only organizations
that adhere to
Mattermost's
Software and
Hardware
Requirements can
qualify for any
support whatsoever.
The overhead
required to
assemble, launch,
and administer
Mattermost is not
insignificant, and
combined with the
monthly per user
cost for support, can
become a
significant burden
over time.
HOWEVER, THEY
OFFER DISCUNTS
TO NON PROFITS.
$100 per month via
private SELF
HOSTING; they
also offer CLOUD
based hosting
BRONZE level is $2
per user per month
or $20 annually.
HOWEVER, THEY
OFFER DISCUNTS
TO NON PROFITS.
Confirmed 70%
discount to 0.60
cents per user
starting at 150 users
payable either
annually or quarterly
via PayPal or cc.
FREE - told Fortune
Mag eventually it
will start charging
businesses, BUT
ANYONE THAT
CREATES AN
ACCT NOW UP TO
1000 USERS WILL
BE
GRANDFATHERED
IN FOR FREE FOR
LIFE. The only
charges added in
tiers will be if they
add new features.
But grandfathered in
users will keep all
current features
free.
HighSide is
currently free to use
while in beta for
small to medium
sized organizations.
All we ask for in
return is your
honest and valued
feedback so we can
continue improving
our product.
FREE
free end to end
encrypted email
with available
upgrade
Private server
PLATFORM COST
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Computer Wiz
4

5. USER INTERFACE AND FUNCTIONALITY
User interface:
how similar is the
UI to slack?
80% 60% 75% 80% n/a
not similar; on
signal they are
group msgs but
groups have no
limits to number of
members
n/a Private server
Functionality: how
similar is the
functionality to
Slack? (e.g.
channel format)
very similar very similar very similar very similar looks the same
not similar; on
signal they are
group msgs but
groups have no
limits to number of
members
n/a Private server
JobSearchSuperhero.c
om 2019 Research
Semaphor Slack-
ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
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Computer Wiz
5

6. SECURITY LEVEL
JobSearchSuperhero.c
om 2019 Research
Semaphor Slack-
ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
Security level
Semaphor features
end-to-end
encryption,
including encryption
while data is at-rest.
All messages and
attachments are
encrypted before
leaving a user's
device and can only
be decrypted by the
intended recipients.
Semaphor performs
all of these functions
in the background,
giving users an
excellent user
experience while
maintaining the
highest level of
security. Semaphor
2 is based upon
private blockchain
technology, as
opposed to the
previous versions
that used a simpler
hashchain instead.
Mattermost only
offers encryption
while data is in-
transit. Mattermost
offers TSL support,
meaning that
messages and
attachments are
encrypted while in-
transit, but does not
offer encryption for
data at rest.
end to end
encryption
End-to-end
encrypted group
chat app that closely
resembles Slack.
This isn't some
malleable, trusted
SQL database with
team roles in it.
When you create a
team, you begin a
chain of signatures.
Your first link
declares that only
you can append to
the chain. You can
then add other
people. And
technically, people
themselves are
chains, so you're
signing their chains
onto the team chain.
if HighSide receives
a subpoena for
information on a
specific client or
organization, we are
fundamentally
unable to provide
anything other than
the client’s basic
"know your
customer
information," such
as contact details,
IP addresses and if
required by law, the
fully encrypted data
itself.
The private Signal
group chats are
private, however the
MMS group chats
are transmitted via
your cellular
provider..
Messages are
stored on
ProtonMail servers
in encrypted format.
They are also
transmitted in
encrypted format
between our servers
and user devices.
Messages between
ProtonMail users
are also transmitted
in encrypted form
within our secure
server network.
Because data is
encrypted at all
steps, the risk of
message
interception is
largely eliminated.
Private server
Copyright The Talent Mill | Job Search Superhero | Dr Mill
Computer Wiz
6

7. ADMIN PRIVILEGES/ACCESS TIERS
JobSearchSuperhero.c
om 2019 Research
Semaphor Slack-
ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
Admin privileges,
access tiers
Only a channel
Administrator of this
Team can ban
someone, edit, or
delete a channel,
etc. For that reason
they recommend
that every channel
have at least 2
administrators, in
case one moves on
or suffers a
technical problem. It
is also poss to setup
a team in such a
way that any team
member can create
a new channel.
There are four types
of user roles with
different permission
levels in
Mattermost: System
Admins, Team
Admins, Members,
and Inactive
accounts. Like
Slack each admin
level has less
access than the
previous one.
A safe workspace
with username
restriction and
admin transparency.
Remove bad actors
by adding
moderators and
provide admins with
additional controls.
It’s still in the works,
so it may not have
all the features or
polish of other apps
that have been
around for a bit –
and you’ll need to
run certain tasks,
like managing team
roles, from the
command line. Only
admins have full
privileges on the
chain and the ability
to add or remove
members. You need
to make the
important people in
the org admins and
owners. You can
create dedicated
sub teams that are
cryptographically
partitioned off.
Inside each team,
there are multiple
chat channels
allowed. Inside a
specific team,
anyone can join any
channel.
facebook page
messaging & email
n/a n/a Private server
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Computer Wiz
7

8. LIMITS ON FREE VERSION
JobSearchSuperhero.c
om 2019 Research
Semaphor Slack-
ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
Are there any
limits of
constraints on the
free service that
force you to
switch to a paid
option? (e.g. max
users or
messages)
Semaphor teams of
five or fewer users
are free. These
teams include all of
the features of paid
teams.
Starting with the
sixth member of a
team, each user is
$10 per month.
SpiderOak offers
discounts to non-
profits, teams in
education, the
military, and
government. Large
teams of 50 or more
users are also
eligible for a
discount.
Contact our support
team to discuss the
pricing we can offer
your team!
https://spideroak.su
pport/hc/en-
us/requests/new
Starts at $3.25 per
month billed
annually. Team
Edition: FREE
Forever. Free trial
no credit card
required.
free is limited to
1000 notifications,
no tech support or
analytics reporting.
BRONZE LEVEL
CLOUD BASED
AVAILABLE as
opposed to SELF
HOSTED/MANAGE
D for $2 per user
per month or $20
annually.
Presently, a team
can support up to
1,000 people – but
that limitation will be
lifted later on. We
think someday if
teams take off, we'll
charge for larger
teams. Nothing
we're offering for
free now will flip to a
pay model, so if you
make a 500 person
team now and start
using it, you won't
someday be faced
with a credit card
screen just to get
your files or
messages. Put most
simply, we
eventually want to
find a way for actual
enterprises to pay,
while keeping
personal and
community use free.
And any use now is
grandfathered in.
There is no upsell
on message history.
It's free to get to
your old messages.
facebook page
messaging & email
n/a
Sending limit: 50
messages/hour and
150 messages/day.
Labels limit: 20
Storage: 500 MB,
Custom domains:
not supported,
Additional
addresses: not
supported,
Customer support:
limited, Short email
domain (@pm.me):
receive messages
only
Private server
Copyright The Talent Mill | Job Search Superhero | Dr Mill
Computer Wiz
8

9. ANY DESKTOP APP?
JobSearchSuperhero.c
om 2019 Research
Semaphor Slack-
ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
Desktop app
YES Apple,
Windows
yes
yes Windows,
Linux, Apple
yes - Apple,
Windows, Linux,
Chrome browser
plugin
NO - If HighSide
were to offer a web
app (like Slack,
HipChat and others)
and HighSide's
servers were
compromised by
hackers, the
attacker could easily
substitute code
stored on our server
with malicious code
and compromise all
user accounts,
messages & files.
yes mac and
windows
yes browser app Private server
Copyright The Talent Mill | Job Search Superhero | Dr Mill
Computer Wiz
9

10. ANY MOBILE APP?
JobSearchSuperhero.c
om 2019 Research
Semaphor Slack-
ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
Mobile app
yes iOS and
android.
Semaphor's mobile
apps work out of the
box without any
additional
configuration
needed. Need to
confirm if there are
push notifications -
there might not be
on mobile.
Mattermost requires
organizations to
compile and self-
distribute the open
source Mattermost
mobile apps, or
open their company
firewall to allow
Mattermost apps
from the public app
stores to connect to
their installation.
Some reviews say
android and iOS
apps are very slow.
yes iOS and android yes - iOS, Android yes iOS and android
yes mac and
windows
yes iOS and
Android
Private server
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Computer Wiz
10

11. CAN YOU IMPORT SLACK ARCHIVES?
HOW WIDELY IS IT USED?
JobSearchSuperhero.c
om 2019 Research
Semaphor Slack-
ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
Can you import
channel content
from Slack?
Imports from slack
will likely never be
available because it
entails security &
privacy trade-offs
that company not
willing to make
yes channels,
users, etc can be
imported from slack.
yes using Slack
Importer & Slack
Bridge AVAILABLE
IN PAID TIERS
No most folks who
have left slack just
keep it running to
access their stuff
until they close acct.
planning on adding
functionality within
one year
n/a n/a Private server
How widely is it
used? (e.g.
number of users
or teams)
N/A
EFF uses it, no
other info found
N/A
Today, Keybase has
335,537+ users and
51,569 teams.
for last 3 yrs they
have brough on
thousands os users
in military, govt,
healthcare, finance
Signal Messenger
has 934,927
monthly app
downloads.
in 2015 Protonmail
had signed up to
500k users
Private server
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Computer Wiz
11

12. DO ANY MAJOR ORG’S USE
OR RECOMMEND IT?
JobSearchSuperhero.c
om 2019 Research
Semaphor Slack-
ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
Do any major
organizations or
figures use or
recommend it?
info pending as
support tech not
sure what Org in
their userbase has
authorized them to
mention them by
name.
EFF uses it
blockchain projects
such as Aragon,
Brave, Hyperledger,
Golem, Tokenly and
others have
migrated from slack
to use Rocket Chat
Ryan T. Hosford
a/k/a @rthbound
who worked in F2BI
slack, and
Progressive Coders
Network with
Pamela and Steven
Scapalleti. He was
also in Bernie
slacks. Primarily
tech companies are
adopting them
because they
understand
Keybase is doing
the cryptography
correctly. They don't
talk about who uses
them but some
famous users are
randomly listed on
home page: Taylor
Swift, Shannon
Morse host &
producer of online
media about tech.
Mostly tech and
journalists using
platform.
works with govt orgs
in uk and us -
finance, healthcare,
military
Ed Snowden
many orgs are using
it even as a
complement to
gmail for their
private
communications.
Private server
Copyright The Talent Mill | Job Search Superhero | Dr Mill
Computer Wiz
12

13. HOW ARE THEIR REVIEWS?
JobSearchSuperhero.c
om 2019 Research
Semaphor Slack-
ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
How are the
reviews?
3 star - GOOD.
CONS: Expensive.
No integrations.
Lacks audio or
video call
capabilities. Few
customization
options. No web
interface. No push
notifications on
mobile. Occasional
stutters on desktop
in testing.
Despite being a
4star from 69
reviews one of the
reviews troubles
me: "the version for
android or iphone is
really slow, have
problems to send
files and i logout
multiple times, this
need more work,
when i try open this
need long time to
open, the alerts is
good but the app is
very slow."
3.5 stars out of 33
reviews. "If you
have a company
larger than ~10
people it would be
better to use
something already
working. If its for a
group project and
you only need to
message one
person at a time or
as a full group then
it could work."
3.5 stars out of 14
reviews
5 stars
Ed Snowden has
recommended it
several times
6.7 out of 10 Private server
Apple App Store
reviews
n/a
2.9 stars, 50
reviews
3.4 stars, 7 reviews n/a n/a n/a n/a Private server
Copyright The Talent Mill | Job Search Superhero | Dr Mill
Computer Wiz
13

14. WHO OWNS THE COMPANY?
JobSearchSuperhero.c
om 2019 Research
Semaphor Slack-
ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
Who owns the
company?
SpiderOak was
founded in 2007 by
Ethan Oberman and
Alan Fairless as an
encrypted private
backup program.
SpiderOak's
President is Mike
McCamon. In 2013,
SpiderOak began
developing the
Crypton framework,
"a JavaScript
framework for
building applications
where the server
doesn't know the
contents it's storing
on behalf of users."
Ian Tien - CEO and
co-founder.
Previously founded
Spin Punch a video
game messaging
app. When Slack
held their messages
hostage they
decided to build
their own internal
communications
app.
Gabriel Engel
founder & CEO
Built by the folks
behind OkCupid and
SparkNotes, the
service is currently
in alpha, is
completely free and
promises to keep
conversations
hidden from prying
eyes, even if your
company’s servers
are hacked.
Keybase was
launched in 2014 by
co-founders Chris
Coyne and Maxwell
Krohn, who
previously founded
dating website
OKCupid in the
early 2000s. The
company has raised
$10.8 million.
Brendan Diaz is Co-
founder & CEO of
ClearChat, Inc.
ClearChat became
HighSide in 2017.
Highside domain is
registered by
Jonathan Warren of
ClearChat
Communications,
Inc in NYC.
Private server
founded in 2014 at
the CERN research
facility by Andy Yen,
Jason Stockman,
and Wei Sun
Private server
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Computer Wiz
14

15. NOTES
JobSearchSuperhero.c
om 2019 Research
Semaphor Slack-
ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
Notes n/a n/a
Free audio and
video conferencing,
guest access,
screen sharing, file
sharing, LiveChat,
LDAP Group Sync,
two-factor
authentication
(2FA), E2E
encryption, SSO,
and dozens of
OAuth providers.
Also includes
UNLIMITED: Users,
channels, searches,
messages, guests,
file uploads.
Keybase was
launched by the co-
founders of
OKCupid all the way
back in 2014. The
company made
headlines in early
March 2018 for
receiving an
investment from the
Stellar Development
Foundation (as
reported exclusively
by Coindesk).
Stellar is the world’s
eight largest
blockchain, and
provides cheap and
fast transfers as
well as minimal
environmental
impact The
company has also
previously received
$10.8 million in
funding during a
venture round led by
Andreesen
Horowitz. Keybase
has a history with
Stellar’s chief
scientist, David
Mazieres.
The inquiring Govt
agency once they
cannot read any
data may then
choose to approach
the HighSide client
directly for
additional
information or to
request the keys for
decrypting the data.
On February 21,
2018, a nonprofit
entity called the
Signal Foundation
was created with an
initial funding of $50
million from
WhatsApp co-
founder Brian Acton,
"to support,
accelerate, and
broaden Signal’s
mission of making
private
communication
accessible and
ubiquitous"
ProtonMail is an
end-to-end
encrypted email
service founded in
2014 at the CERN
research facility by
Andy Yen, Jason
Stockman and Wei
Sun. ProtonMail
uses client-side
encryption to protect
email contents and
user data before
they are sent to
ProtonMail servers,
in contrast to other
common email
providers such as
Gmail and
Outlook.com.
Private server
Copyright The Talent Mill | Job Search Superhero | Dr Mill
Computer Wiz
15

16. COULD WE PRIVATELY HOST
COLLABORATION SOFTWARE
JobSearchSuperhero.c
om 2019 Research
Semaphor Slack-
ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
Could we privately
host it?
cloud based
blockchain
technology
yes you MUST
privately host it with
Linux server
hardware
yes BUT THEY
ALSO OFFER A
CLOUD BASED
SOLUTION
cloud based
blockchain
technology
facebook page
messaging & email
The project receives
donations via the
Freedom of the
Press
Foundation,[135][13
6] which has acted
as Open Whisper
Systems' fiscal
sponsor since
December
2016.[137][138]
Open Whisper
Systems has
received grants
from the Knight
Foundation,[139]
the Shuttleworth
Foundation,[140]
and the Open
Technology Fund, a
U.S. government–
funded program that
has also supported
other privacy
projects like the
anonymity software
Tor and the
encrypted instant
messaging app
Cryptocat.[141]
servers are located
at two locations in
Switzerland, outside
of US and EU
jurisdiction
Private server
Copyright The Talent Mill | Job Search Superhero | Dr Mill
Computer Wiz
16

17. SUPPORT TYPE
JobSearchSuperhero.c
om 2019 Research
Semaphor Slack-
ALT
Mattermost
Slack-ALT
Rocketchat
Slack-ALT
Keybase Slack-
ALT
ClearChat by
HighSide Slack-
ALT
Signal / Phone
Messaging
Aternative to
Gmail
Alternative to
Cloud
Support type
Semaphor includes
Tier 1 support with
all user accounts,
and Enterprise-level
support with Pro
plans. SpiderOak's
support team offers
Tier 1 support for
Semaphor account
admins and end
users. Enterprises
qualify for onsite
training and optional
assisted
deployment as well.
tech support is
limited to forum if on
free version, and
gets better in paid
tiers.
email tech support
for free accts, and
tech support gets
better for the paid
tiers.
There is no direct
support like there
would be on a paid
project. But it looks
like tips and help
are available via a
Keybase Support
Chat and/or through
a GitHub and Reddit
forum. There is also
a 'keybasefriends'
semi active
community on
keybase that helps
answer questions.
facebook page
messaging & email
email
zendesk
support@protonmail
.com
Private server
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