<s>
Zcash	B-Protocol
is	O
a	O
cryptocurrency	O
aimed	O
at	O
using	O
cryptography	O
to	O
provide	O
enhanced	O
privacy	O
for	O
its	O
users	O
compared	O
to	O
other	O
cryptocurrencies	O
such	O
as	O
Bitcoin	B-Protocol
.	O
</s>
<s>
Zcash	B-Protocol
is	O
based	O
on	O
Bitcoin	B-Protocol
's	O
codebase	O
.	O
</s>
<s>
Transactions	O
can	O
be	O
"	O
transparent	O
"	O
and	O
similar	O
to	O
bitcoin	B-Protocol
transactions	O
in	O
which	O
case	O
they	O
are	O
controlled	O
by	O
a	O
t-addr	O
,	O
or	O
they	O
can	O
be	O
"	O
shielded	O
"	O
and	O
are	O
controlled	O
by	O
a	O
z-addr	O
.	O
</s>
<s>
A	O
shielded	O
transaction	O
uses	O
a	O
type	O
of	O
zero-knowledge	B-Protocol
proof	I-Protocol
called	O
zk-SNARKs	B-Application
,	O
which	O
provides	O
anonymity	O
to	O
the	O
coin	O
holders	O
in	O
the	O
transaction	O
.	O
</s>
<s>
Zcash	B-Protocol
coins	O
are	O
either	O
in	O
a	O
transparent	O
pool	O
or	O
a	O
shielded	O
pool	O
.	O
</s>
<s>
As	O
of	O
December	O
2017	O
only	O
around	O
4%	O
of	O
Zcash	B-Protocol
coins	O
were	O
in	O
the	O
shielded	O
pool	O
and	O
at	O
that	O
time	O
most	O
cryptocurrency	B-Protocol
wallet	I-Protocol
programs	O
did	O
not	O
support	O
z-addrs	O
and	O
no	O
web-based	O
wallets	O
supported	O
them	O
.	O
</s>
<s>
The	O
shielded	O
pool	O
of	O
Zcash	B-Protocol
coins	O
were	O
further	O
analyzed	O
for	O
security	O
and	O
it	O
was	O
found	O
that	O
the	O
anonymity	O
set	O
can	O
be	O
shrunk	O
considerably	O
by	O
heuristics-based	O
identifiable	O
patterns	O
of	O
usage	O
.	O
</s>
<s>
Zcash	B-Protocol
affords	O
private	O
transactors	O
the	O
option	O
of	O
"	O
selective	O
disclosure	O
"	O
,	O
allowing	O
a	O
user	O
to	O
prove	O
payment	O
for	O
auditing	O
purposes	O
.	O
</s>
<s>
While	O
miners	O
receive	O
80%	O
of	O
a	O
block	O
reward	O
,	O
20%	O
is	O
given	O
to	O
the	O
"	O
Zcash	B-Protocol
development	O
fund	O
"	O
:	O
8%	O
to	O
Zcash	B-Protocol
Open	O
Major	O
Grants	O
,	O
7%	O
to	O
Electric	O
Coin	O
Co.	O
,	O
and	O
5%	O
to	O
The	O
Zcash	B-Protocol
Foundation	O
.	O
</s>
<s>
Development	O
work	O
on	O
Zcash	B-Protocol
began	O
in	O
2013	O
by	O
Johns	O
Hopkins	O
professor	O
Matthew	O
Green	O
and	O
some	O
of	O
his	O
graduate	O
students	O
.	O
</s>
<s>
The	O
development	O
was	O
completed	O
by	O
the	O
for-profit	O
Zcash	B-Protocol
Company	O
,	O
led	O
by	O
Zooko	O
Wilcox	O
,	O
a	O
Colorado-based	O
computer	O
security	O
specialist	O
and	O
cypherpunk	O
.	O
</s>
<s>
IN	O
October	O
2016	O
,	O
The	O
Zcash	B-Protocol
Company	O
raised	O
over	O
$3	O
million	O
from	O
Silicon	O
Valley	O
venture	O
capitalists	O
to	O
complete	O
the	O
development	O
of	O
Zcash	B-Protocol
.	O
</s>
<s>
Zcash	B-Protocol
was	O
first	O
mined	O
in	O
late	O
October	O
2016	O
.	O
</s>
<s>
The	O
initial	O
demand	O
was	O
high	O
,	O
and	O
within	O
a	O
week	O
Zcash	B-Protocol
coins	O
were	O
trading	O
for	O
five	O
thousand	O
dollars	O
a	O
piece	O
.	O
</s>
<s>
Ten	O
percent	O
of	O
all	O
coins	O
mined	O
for	O
the	O
first	O
four	O
years	O
were	O
to	O
be	O
allotted	O
to	O
the	O
Zcash	B-Protocol
Company	O
,	O
its	O
employees	O
,	O
the	O
investors	O
,	O
and	O
the	O
non-profit	O
Zcash	B-Protocol
Foundation	O
.	O
</s>
<s>
The	O
setup	O
of	O
Zcash	B-Protocol
required	O
the	O
careful	O
execution	O
of	O
a	O
trusted	O
setup	O
procedure	O
—	O
something	O
that	O
subsequently	O
became	O
known	O
as	O
"	O
The	O
Ceremony	O
"	O
—	O
to	O
create	O
the	O
Zcash	B-Protocol
private	B-Application
key	I-Application
.	O
</s>
<s>
In	O
order	O
to	O
ensure	O
the	O
privacy	O
characteristic	O
of	O
Zcash	B-Protocol
it	O
is	O
important	O
to	O
generate	O
a	O
truly	O
random	B-Algorithm
enormous	O
number	O
that	O
can	O
be	O
used	O
as	O
the	O
private	B-Application
key	I-Application
,	O
while	O
also	O
ensuring	O
that	O
no	O
person	O
or	O
computer	O
retains	O
a	O
copy	O
of	O
the	O
key	O
,	O
or	O
could	O
subsequently	O
regenerate	O
the	O
key	O
.	O
</s>
<s>
If	O
the	O
private	B-Application
key	I-Application
were	O
available	O
to	O
anyone	O
,	O
they	O
could	O
generate	O
counterfeit	O
Zcash	B-Protocol
coins	O
,	O
destroying	O
the	O
Zcash	B-Protocol
system	O
.	O
</s>
<s>
The	O
private	B-Application
key	I-Application
was	O
generated	O
,	O
and	O
used	O
to	O
instantiate	O
Zcash	B-Protocol
,	O
and	O
the	O
computers	O
used	O
in	O
the	O
process	O
were	O
reportedly	O
destroyed	O
.	O
</s>
<s>
On	O
May	O
12	O
,	O
2017	O
,	O
regarding	O
the	O
WannaCry	O
ransomware	O
attack	O
and	O
Zcash	B-Protocol
's	O
compliance	O
with	O
global	O
anti-money	O
laundering	O
standards	O
,	O
Zooko	O
Wilcox	O
wrote	O
:	O
"	O
I	O
think	O
we	O
can	O
successfully	O
make	O
Zcash	B-Protocol
too	O
traceable	O
for	O
criminals	O
like	O
WannaCry	O
,	O
but	O
still	O
completely	O
private	O
&	O
fungible	O
.	O
</s>
<s>
On	O
March	O
1	O
,	O
2018	O
,	O
Ariel	O
Gabizon	O
,	O
an	O
employee	O
of	O
the	O
Zcash	B-Protocol
Company	O
,	O
discovered	O
a	O
critical	O
bug	O
which	O
could	O
have	O
allowed	O
an	O
attacker	O
to	O
create	O
an	O
infinite	O
amount	O
of	O
counterfeit	O
Zcash	B-Protocol
.	O
</s>
<s>
On	O
October	O
28	O
,	O
2018	O
,	O
the	O
fix	O
for	O
this	O
issue	O
was	O
covertly	O
included	O
in	O
the	O
Sapling	O
network	O
upgrade	O
to	O
the	O
Zcash	B-Protocol
network	O
.	O
</s>
<s>
On	O
February	O
21	O
,	O
2019	O
,	O
the	O
"	O
Zcash	B-Protocol
Company	O
"	O
announced	O
a	O
re-branding	O
as	O
the	O
Electric	O
Coin	O
Company	O
(	O
ECC	O
)	O
.	O
</s>
<s>
In	O
their	O
blog	O
post	O
,	O
the	O
company	O
claims	O
that	O
they	O
had	O
been	O
calling	O
themselves	O
the	O
"	O
Zcash	B-Protocol
Company	O
"	O
but	O
that	O
their	O
legal	O
name	O
has	O
always	O
been	O
the	O
Zerocoin	B-Protocol
Electric	O
Coin	O
Company	O
,	O
LLC	O
and	O
that	O
they	O
will	O
now	O
be	O
known	O
as	O
the	O
ECC	O
.	O
</s>
<s>
On	O
September	O
24	O
,	O
2019	O
,	O
the	O
ECC	O
announced	O
that	O
Zcash	B-Protocol
was	O
compliant	O
with	O
all	O
requirements	O
arising	O
from	O
the	O
Financial	O
Action	O
Task	O
Force	O
(	O
FATF	O
)	O
anti-money-laundering	O
recommendations	O
in	O
a	O
company	O
blog	O
post	O
titled	O
"	O
How	O
Zcash	B-Protocol
is	O
Compliant	O
with	O
the	O
FATF	O
Recommendations	O
"	O
.	O
</s>
<s>
On	O
May	O
19	O
,	O
2020	O
,	O
a	O
paper	O
titled	O
"	O
Alt-Coin	O
Traceability	O
"	O
investigated	O
the	O
privacy	O
of	O
both	O
Zcash	B-Protocol
and	O
Monero	B-Protocol
.	O
</s>
<s>
This	O
paper	O
concluded	O
that	O
"	O
more	O
academic	O
research	O
is	O
needed	O
in	O
Zcash	B-Protocol
overall	O
"	O
and	O
that	O
the	O
privacy	O
guarantees	O
of	O
Zcash	B-Protocol
are	O
"	O
questionable	O
"	O
.	O
</s>
<s>
The	O
paper	O
claimed	O
that	O
since	O
the	O
current	O
heuristics	O
from	O
a	O
2018	O
Usenix	O
Security	O
Symposium	O
paper	O
entitled	O
"	O
An	O
Empirical	O
Analysis	O
of	O
Anonymity	O
in	O
Zcash	B-Protocol
"	O
still	O
continue	O
today	O
that	O
the	O
result	O
is	O
making	O
Zcash	B-Protocol
less	O
anonymous	O
and	O
more	O
traceable	O
.	O
</s>
<s>
On	O
June	O
8	O
,	O
2020	O
,	O
Chainalysis	O
added	O
support	O
for	O
Zcash	B-Protocol
to	O
their	O
Chainalysis	O
Reactor	O
and	O
"	O
Know	O
Your	O
Transaction	O
"	O
(	O
KYT	O
)	O
technologies	O
.	O
</s>
<s>
This	O
permits	O
Chainalysis	O
to	O
trace	O
and	O
provide	O
transaction	O
values	O
and	O
at	O
least	O
the	O
sender	O
or	O
receiver	O
address	O
for	O
over	O
99%	O
of	O
Zcash	B-Protocol
activity	O
.	O
</s>
<s>
Chainalysis	O
explains	O
that	O
it	O
is	O
able	O
to	O
accomplish	O
this	O
since	O
most	O
Zcash	B-Protocol
users	O
do	O
not	O
use	O
privacy-enhancing	O
features	O
.	O
</s>
<s>
Chainalysis	O
also	O
cites	O
a	O
research	O
paper	O
by	O
the	O
RAND	O
corporation	O
which	O
revealed	O
that	O
less	O
than	O
0.2	O
%	O
of	O
the	O
cryptocurrency	O
addresses	O
on	O
the	O
dark	O
web	O
were	O
Zcash	B-Protocol
addresses	O
.	O
</s>
<s>
A	O
majority	O
of	O
the	O
investors	O
and	O
owners	O
of	O
Zerocoin	B-Protocol
Electric	O
Coin	O
Company	O
LLC	O
(	O
ECC	O
)	O
have	O
agreed	O
to	O
donate	O
the	O
ECC	O
company	O
as	O
the	O
wholly	O
owned	O
property	O
of	O
Bootstrap	O
.	O
</s>
