►
From YouTube: The Right to be Forgotten Meets Blockchain: Native GDPR Compliance for Hyperledger...-Yacov Manevich
Description
The Right to be Forgotten Meets Blockchain: Native GDPR Compliance for Hyperledger Fabric - Yacov Manevich, IBM
Append-only structures such as blockchain, never forget their past. Once user data gets into a block, it stays there forever. The right to be forgotten seems to be in conflict with this nature, and at first glance, erasure of user data and blockchains, cannot coexist. We present how GDPR compliance can be easily and simply incorporated into Hyperledger Fabric in a native manner, which grants users with the right to be forgotten. Our design draws from Hyperledger Fabric's unique architecture, and modifies the block structure in a backward compatible manner, eliminating user data from the blockchain without sacrificing correctness or consistency . We evaluated our solution and found that it provides GDPR compliance with only a minimal performance overhead, making it a viable solution for Hyperledger Fabric or any other execute-order-validate type blockchain.
Session Details & Slides (if available)- https://sched.co/j3bR
Access All Sessions: https://events.linuxfoundation.org/hyperledger-global-forum/program/schedule/
----
Hyperledger – Open Source Blockchain Technologies
Hyperledger is an open source community focused on developing a suite of stable frameworks, tools and libraries for enterprise-grade blockchain deployments.
It serves as a neutral home for various distributed ledger frameworks including Hyperledger Besu, Fabric, Sawtooth, Indy, as well as tools like Hyperledger Avalon, Cactus and libraries like Hyperledger Aries, Ursa. Learn more about Hyperledger projects: https://www.hyperledger.org/use
Case Studies: https://www.hyperledger.org/learn/case-studies
Training & Certification: https://www.hyperledger.org/learn/training
Tutorials: https://www.hyperledger.org/use/tutorials
Webinars: https://www.hyperledger.org/learn/webinars
Events: https://www.hyperledger.org/events
Vendor Directory: https://www.hyperledger.org/use/vendor-directory
Subscribe to the Hyperledger Newsletter: https://www.hyperledger.org/newsletter
Follow-us on Twitter @Hyperledger
Learn about Hyperledger Membership: https://www.hyperledger.org/about/join
#Hyperledger #HyperledgerGlobalForum2021 #Blockchain
A
All
right,
I
see
we
have
about
like
20
people
here,
so
I
guess
I
can
start,
and
so
I'm
going
to
go
over
a
presentation,
and
I
you
can
leave
your
questions
in
the
q
a
section
and
I'm
going
to
to
take
a
peek
at
the
q
a
from
time
to
time
right.
So
what
I'm
going
to
talk
to
you
about
today
is
a
way
of
reducting
transactions
from
fabric,
but
this
technique
is
not
limited
to
fabric.
A
You
can
also
employ
it
in
in
other
blockchains
that
are
that
have
a
similar
architecture,
a
such
as
fabric
like
in
execute
order,
validated
blockchains
and
I'm
yakovanevich,
and
this
is
joint
work
with
the
arthur,
berger
and
god.
Assa
arthur
is
a
my
colleague
from
ibm.
Research
in
haifa,
israel
and
gal
is
from
the
technion
in
israel
and
by
the
way,
can
you
guys
hear
what
I
say?
Can
you
yeah?
We
can
hear
you
okay
thanks.
A
So
I
guess
I
don't
need
to
go
over
this
slide.
You
all
know
a
hydrogen
fabric,
a
permission,
blockchain
platform
in
the
linux
foundation,
and
it
has
two
incomplete
smart
contracts.
You
can
write
smart
contracts
in
basically
any
supported
language
like
go
javascript
java
and
one
of
the
the
things
that
differentiate
fabric
from
other
blockchains
is
that
it
has
a
unique
architecture,
which
is
the
execute
order
validate
paradigm.
A
A
A
Then
the
sdk
takes
all
of
these
endorsements
stitches
them
together
and
sends
a
and
creates
a
transaction
signs
of
this
transaction
and
sends
this
transaction
to
the
ordering
service.
Now
an
ordering
service
is
a
cluster
of
several
nodes
where
each
node
is
called
an
order
in
service
node,
and
the
role
of
the
ordering
service
is
to
actually
create
a
blockchain
itself.
A
So
these
these
nodes,
they
they
create
a
by
running
some
kind
of
consensus
algorithm
they
create
the
blocks
the
blocks
are
disseminated,
appears
and
then
the
peers
validate
the
transactions
and
only
apply
the
valid
transactions
and
transactions
that
that
are
deemed
invalid.
They
are
simply
ignored,
however,
as
you
know,
the
transactions
they
all
end
up
in
the
ledger
in
the
blockchain.
A
Let's
see
if
there
are
any
questions,
no
no
questions
yet
so,
let's,
like
let's
say,
go
over
something
completely
unrelated
to
fabric,
which
is
the
gdpr
about
about.
Five
years
ago,
the
european
parliament
came
up
with
a
set
of
laws
and
regulations
that
basically
mandate
how
or
how
our
companies
and
organizations
inside
europe
how
they
deal
with
data.
A
So
the
the
the
regulations
specify
three
types
of
actors.
You
have
data
subjects
which
are
really
people
whose
personal
data
is
processed
by
entities
called
data,
processors
and
the
data
processors.
Usually
they
are
servers.
They
are
entities
that
that
they
process
the
data
of
the
data
subjects.
On
behalf
of
the
data
controllers,
which
are
entities
that
determine
the
purpose
of
the
processing
data
of
the
data
subjects.
A
A
For
example,
you
cannot
process
it
for
a
for
a
reason
that
is
not
known
to
the
subject.
Also,
you
need
to
minimize
the
amount
of
data
that
you
keep
in
order
to
processing
you
know
for
the
processing.
It
do
not
like
store
information.
If
you
don't
need
it
also,
when
you
store
the
data,
it
needs
to
be
accurate,
meaning
that
the
data
subject
has
a
right
to
correct
the
data
that
you
store
about
him
or
her
and
storage
limitations.
A
Of
course,
of
course,
there
are
all
kinds
of
corner
cases
such
as
financial
data,
but
let's
not
talk
about
them,
and
what
I
want
to
focus
on
is
the
following
thing:
that
basically
a
blockchain
and
the
gdpr
are
con,
are
a
contradiction
because
the
right
to
be
forgotten
regulation-
it's
it
requires
deletion
of
transaction
data
from
the
past.
However,
if
you
delete
data
from
the
past,
you
change
the
the
data
that
the
the
that
that
the
network
nodes
see
in
the
future.
A
You
change
this
data
and
we
know
that
blockchain
is
all
about
immutability.
Each
block
contains
the
hash
of
the
previous
block,
for
example
transactions.
They
are
all
cryptographically
signed
right.
So
if
you
change
any
data
in
a
transaction,
then
the
signature
will
no
longer
will
no
longer
be
valid.
A
Gdpr
is
about
personal
data
fabric
currently
is
used
mostly
in
enterprise
for
business
transactions.
What
do
you
think
is
the
person
data
in
the
transactions?
Yeah,
that's
a
good
question,
so
we
it
can
be
all
kinds
of
data,
for
example
medical
data,
maybe
sometimes
data
about
financial
data
or
data
about
if
you
use
like
fabric
to
audit
all
kinds
of
things
like
cert,
like
certificates
of
people,
basically
anything
that
can
be
related
to
some
person.
A
A
A
So
a
chameleon
hash
function
is
basically
a
function,
a
hash
function
that
uses
public
key
cryptography
and
it
allows
you
it
allows
someone
that
knows
a
trapdoor,
a
a
a
chapter
of
the
hash
function.
It
allows
that
person
to
create
a
hash
collision.
So
you
see
here
in
this
example,
the
the
hash
of
the
hash
is
given
in
blue
and
in
the
blue
rectangle,
and
the
hash
of
the
green
rectangle
is
the
correct
hash.
However,
if
someone
knows
the
chapter,
it
can
create
a
hash
collision.
A
The
chapter
basically
allows
you
to
to
carefully
select
a
string
which,
under
the
chameleon
hash
function,
you
will
create
a
hash
collision
and
you
will
map
this.
This
string
in
the
red
rectangle.
You
will
map
it
to
the
same
string
in
the
blue
rectangle,
and
how
do
you
use
this
in
in
in
reducting
data
in
blockchains?
So
that's
basically
imagine
that
you
have
the
this
blockchain
on
top.
A
You
have
this,
these
blue
blocks,
and
if
you
know
the
chapter,
then
you
can
you
can
alter
the
content
of
the
this
middle
block
and
create
a
different
clock
which
is
orange
and
and
then
you
you
can
use
this
technique
to
reduct
trans
data
in
transactions.
Basically,
you
can
use
this
technique
to
delete
information
of
users
right
to
comply
to
gtpr.
A
However,
there
is
one
small
problem,
and
that
is
if
someone
knows
this
chapter,
it
can
also
maliciously
alter
the
entire
blockchain,
and
this
is
a
problem
right.
Why?
Because
that
person
actually
can
can
fork
the
entire
it
can
that
person
can
fork
all
of
the
nodes
in
the
entire
network
and
some
works
in
the
in
the
academia
in
the
literature
literature
they
propose
all
kinds
of
solutions.
A
For
example,
let's
maybe
have
one
trapdoor
for
one
block
is
still
a
problem,
because
this
chapter
it
can
be
leaked
right,
it
can
be
stolen
and
it
can
be
used
maliciously
and
then
other
academic
works
came
and
say,
okay
and
said.
Okay,
let's
take
this
chapter,
we
will
split
it
into
many
secret
shares
and
we
use
multi-party
computation
cryptographic
techniques
to
compute
the
chap
compute,
the
hash
collision
without
any
party.
A
So
if
you
are
a
peer,
you
you
can,
you
can
look
at
the
block
and
you
can
and
when
you
validate
the
transaction,
you
never
look
at
the
value
of
the
key.
Only
about
the
you
only
look
at
like
a
at
the
signatures
or
of
the
mvcc
version
of
that
key,
but
you
never
look
at
the
value,
and
this
means
that
appear
that
joined
much
much
later
after
that
data
has
been
rejected.
A
So
let's
see
some
more
questions,
information
as
an
asset
I
get
in
an
asset
in
my
platform
and
then
give
the
owner
the
asset
asset,
not
not
really
so
so
anonymous
asked
a
question,
so
the
answer
is
not
really.
Basically,
if
you
delete
the
data
after
it
has
been
processed
all
peers
that
have
have
processed
this
data
in
the
past,
they
they
already
recorded
this
data
in
their
world
state
database.
So
they
don't
really
need
the
ledger.
A
So
someone
asked,
in
your
opinion,
putting
data
on
the
pdc
and
then
removing
it
from
ptc
can
be
interpreted
as
implementation.
That's
a
that's
a
great
question.
Indeed,
that
is
one
of
the
ways
that
customers
and
users
implement
implement
this.
This
requirement
now,
however,
in
fabric,
it
is
still
not
possible
to
manually
in
in
explicitly
delete
the
ptc
data.
You
need
to
wait
for
this
block
to
leave
parameter
blocks
to
pass,
and
this
is
why
pay
is
still
not
gdpr
compliant.
A
A
A
So
what
we're
going
to
do
is
simply
replace
these
fields
instead
of
putting
the
value
we
replace
them
with
their
hashes,
and
then
we
still
need
the
pre-images
of
the
hashes
right.
So
we
we
simply
allocate
a
new
space
in
the
transaction,
which
we
call
a
pre-image
space
and
there
we
simply
dump
all
of
the
pre-images
just
as
in
this
slide
now,
in
a
nutshell,
the
technique
that
we
implemented
and
also
benchmarked
it
allows
you
to
reduct
data
on
chain
in
fabric.
A
It
goes
like
this.
The
first
thing
we
need
to
do
is
relocate
user
data
to
a
special
place
in
in
the
transaction.
Just
as
I
said
so,
you
see
on
the
left.
You
see
the
transaction
structure
before
and
on
the
right.
You
see
the
transaction
structure
after
so
now
after
this
change,
the
the
value
in
the
transaction,
it
contains
the
hash
and
there
is
a
separate
place
in
the
transaction
which
is
not
signed.
A
You
see,
the
signature
is
only
signing
over
the
payload.
However,
the
pre
images
is
now
taken
out
of
the
payload.
The
second
thing
you
need
to
do
is
replace
the
the
original
user
data
with
hashes.
Just
as
I
said,
and
now
another
very
important
thing
is
you
basically
need
to
migrate
these
these
pre-images?
A
You
need
to
migrate
them
in
all
the
messages
that
that
are
involved
in
the
fabrics
in
fabric's
transaction
life
cycle.
So
in
the
peer
side,
when
the
peer
creates
its
endorsement
and
the
proposal
response,
it
allocates
a
new
pre-image
space.
Just
for
that
then,
the
client-
it
extracts
all
of
these
pre-images
in
the
in
the
response
and
puts
them
in
a
new
place
in
the
in
the
actual
transaction,
and
then
when
the
client,
the
sdk
sends
this
transaction
to
the
order.
A
The
order
also
does
something
similar.
It
basically
strips
out
all
of
these
three
images
from
each
transaction
and
puts
all
per
images
in
a
special
place
in
the
block
called
a
pre-image
space,
and
in
this
in
in
this
way,
the
the
data
of
the
block,
which
contains
the
transactions
it
never
contains
any
pre-images
all
the
primitives
are
in
a
special
place.
A
A
However,
there
is
a
problem
with
doing
that,
and
the
problem
is
is
actually
related
to
something
that
someone
asked,
and
that
problem
is
that,
let's
assume
it's
a
situation
where
we
have
a
peer
that
joined
the
network
before
a
a
reduction,
and
let's
assume
that
in
block
100
you
you,
you
have
a
value,
a
bar
and
this
value
is
being
assigned
to
a
key
for
right.
So
transaction
3
assigns
bar
24
and
then
in
block
102.
A
A
Let's
assume
that
this
sphere,
for
now
it
only
got
block
100
and
it
didn't
get
blocked
103
yet
so
it
is.
It
is
not
aware
that
the
foo
that
the
kifu
has
been
deleted
because
that
beer,
it
is
still
in
block
100,
so
imagine
that
this
spear
now
receives
a
chain
code.
A
a
smart
contract
invocation
request
at
which
it
needs
to
read
the
key
for,
but
it
doesn't
have
the
preimage
of
kifu.
A
So
that's
why
we
add
a
new
constraint,
which
means
that
if
you
as
a
peer,
you
read
a
key
which
was
redacted,
then
you
simply
instantly
abort
this
execution
and
we
mark
these
keys
as
crippled
keys.
Now,
this
crippled
key
will
be
crippled
until
it
will
see
block
103
where,
where
it
will
know
that
the
key
for
is
deleted,
and
then
it
doesn't
need
it
to
remember
it
anymore
as
a
crippled
key
because
it
is,
it
is
deleted
from
all
peers
at
that
block
height.
A
Another
thing
that
you
need
to
do
is
you
need
to
filter
out
transactions
with
missing
hashes,
because,
basically,
a
malicious
client
can
send
a
transaction
with
mismatching
hashes,
and
we
don't
want
to
create
blocks
that
are
not
sound.
So
the
ordering
service
also
needs
to
do
some
processing
and
also
in
order
to
reduce
the
transaction.
You
need
to
collect
signatures
from
the
eligible
parties.
A
A
We
ran
a
total
of
a
1
million
transactions
per
child
in
10
total
trials,
and
we
averaged
the
results
and
each
it's.
Each.
A
transaction
contains
key
rights
to
five
out
of
ten
possible
keys
and
basically
the
overhead
that
we
measured
is
that
if
you
use
a
fabric
with
the
reduction
with
the
reduction
technique,
then
you
get
a
19
a
reduction
in
in
throughput
in.
A
Another
thing
that
appear
now
needs
to
do
a
when
when
it
receives
a
block
from
another
peer,
it
needs
to
basically
validate
the
block.
I'm
not
going
to
to
go
over
this
in
detail
because
we're
lacking
a
time-
and
I
will
to
to
close-
I
want
to
before
I
take
questions
in
the
q-
a
I
will
want
to
also
to
mention
other
approaches
for
complying
with
gdpr
and
blockchains
the
first.
The
first
approach
is
off-chain
storage,
which
is
actually
similar
to
what
a
pdc
private
data
collections
is
doing.
A
A
However,
the
problem
is
that
this
creates
a
data
availability
problem,
because,
if
you,
for
example,
use
pdcs
and
you
for
some
reason,
the
data,
the
the
private
data
hasn't
been
replicated
to
enough
peers,
and
it
appears
that
the
they
did
have
this
private
data
they
crash.
You
may
lose
the
data
with
this
with
our
technique,
you
never
lose
the
data
because
the
data
is
remained
on
chain.
However,
you
can
still
reduce
it.
Another
approach
that
exists
in
the
literature
is
that
you
can
basically
collaborately
sign
on
the
block
replacements.
A
For
example,
if
I
transfer
a
if
I
transfer
a
coin
to
someone,
then
you
cannot
reduce
this
data
because
it
will
create
problems
and
the
final
approach
is
pruning
and
basically,
it
involves
taking
a
snapshot
of
the
state
database,
removing
the
ledger
files
and
then
you
implicitly
reducted
the
ledger
right,
because
you
can
remove
the
ledger
files.
However,
the
problem
here
is
applicability
which
is
lost
when
the
data
files
are
removed.
A
Let
me
see
if
there
are
any
questions.
Where
do
you
stand
in
terms
of
implementation?
That's
a
great
question.
So
let
me
let
me
paste
the
link
to
the
so
we
we
implemented
the
the
the
the
key
parts
which
do
not
do
not
include
the
I
hesitate
in
the
chat
we
we
implemented
the
key
parts.
The
thing
that
we
did
not
implement
are
the
like,
like
the
actual
reduction,
where
you
zero
out
the
bytes
and
also
the
crippled
key.
A
Besides
that
we
implemented
everything
and
the
is
your
proposed
solution
with
premium
segregation
to
implement
prop
productively
or
actively,
I'm
not
sure
what
it
means
proactively
or
actively
benedict
said.
I
really
like
the
idea,
but
doesn't
this
assume
that
all
peers
are
honest?
No,
it
does
not
assume
alters,
are
honest.
There
is
that
slide
with
the
with
the
text,
with
the
text
a
algorithm
and
basically
a
peer
can
verify
if
it
receives
a
if
it
receives
a
block
from
another
peer
that
has
problems
in
it,
and
the
a
dishonest
period
may
not
decide.
A
Oh
okay,
yeah
yeah,
so
it
absolutely
so
you're
correct
benedict.
If
a
dishonest
peer
decides
not
to
delete
the
data,
then
this
the
solution
falls
apart.
However,
this
this
solution,
I
mean
this
problem
that
you
described
existing
in
any
system.
You
will
imagine
right,
because
I
can
take
the
data
and
I
can
post
it
on
facebook
right.
A
A
You
can
still
see
here
that
in
log
files
yeah
that
is
correct
and
if
you
go
to
the
jira,
if
you
go
to
the
jira,
a
rafael,
you
will
see
there
that
the
jira
also
mentioned
machines.
Log
files,
and
also
things
like
that,
oh
mark
was
asked:
does
your
approval
only
apply
to
state
updates,
or
is
it
used
to
deleting
location
spams?
So
that's
a
good
question.
I
you
can
use
the
you
can
use
this
approach
also
for
the
the
invocation
parameters.