Boolberry is a cryptocurrency based on
CryptoNote technology. Boolberry’s major benefit is that it provides
much stronger privacy for both the senders and receivers of
transactions. It does so by ensuring that receivers are anonymous (the
destination of a transaction can only be determined by its real
recipient) and transactions cannot be linked to a single sender.
Instead, each transaction could have many equally possible senders, and
an attacker cannot determine which one it was.
It does so by ensuring that:
receivers are anonymous (the destination of a transaction can only be determined by its real recipient);
Transactions cannot be linked to a single sender; instead, each
transaction could have many equally possible senders, and an attacker
cannot determine which one it was.
Boolberry improves upon the base CryptoNote technology in several
ways that strengthen its anonymity and reduce the size of the global
ledger of all transactions, called the “blockchain”. It provides an
aliasing facility built in to the blockchain so that people or programs
can send money to, for example, “@zoidberg” instead of a long address.
And it has an easy-to-use
GUI wallet that ships in source and binary as an official part of the Boolberry distribution.
Main Features
New cryptography based on ring signatures and one-time transaction keys provides the strongest privacy of any cryptocurrency;
Separated wallet and daemon help improve usability and security;
Flexible RPC-like network protocol provides a basis for flexibly extending the network protocol quickly and robustly;
Blockchain-based PoW hash helps balance CPU, GPU, and ASIC speeds while providing extremely fast block verification;
Outs with guaranteed anonymity
The output of a transaction can be marked so that it can only be later
used with a certain number of mixins. By using only coins thus marked, a
user that mixing her transactions for privacy can ensure that the
transactions remain private over time.
Alerts (signed by developers) broadcast via peer-to-peer mechanism, inform both users and miners of critical updates or other important events
Transaction identification by prefix:
this feature reduces blockchain bloat.pdf by cutting off ring
signatures that are covered by a checkpoint. It can save 30-70% of the
blockchain space, addressing an important drawback to CryptoNote’s
stronger privacy.
Wallet addresses aliasing: Any address can be linked to a
symbolic name and be used globally. By being built into the blockchain,
these aliases are globally unique (original), but do not require a
central naming authority to maintain.
The main ideas of Boolberry transaction generation are explained in the following graph:
Boolberry Compared to Bitcoin
In comparison to Bitcoin forks, Boolberry is developed on newer
CryptoNote technology, making it of more flexible architecture. The main
benefit of CryptoNote technology is anonymity of the sender and
recipient along with transaction unlinkability. This provides great
protection to user’s privacy which is highly important today.
Boolberry benefits:
Ring Signature based cryptography, which ensures new level of privacy, anonymity and unlinkability
Separate Wallet and Daemon provide and additional level of security and cloud compatibility
Flexible RPC-like network protocol with forward and backward capability provides ability to extend network interaction format quickly and painlessly.
New ASIC-Resistant Hash algorithm named Wild Keccack takes the SHA3 Keccak to a higher level.
Boolberry Compared to CryptoNote
Boolberry was designed from the beginning to address several issues
with Ordinary CryptoNote coins such incomplete anonymity and block chain
bloat.
Transaction identification by prefix allows Boolberry to cut ring signatures from block chainreducing block chain size by 60-90%, depending on mixin usage.
Removed Dust from block reward to reduce block chain size even more.
New block chain based PoW hash provides faster synchronization with network and immunity from DoS attacks.
Network Alerts allow developers to broadcast messages about critical updates or other important events to the network
Donation-based crowd-funding: Boolberry has an open and
transparent model of project financing with a maximum of 1% of mined
coins reserved for project development. The actual rate is controlled by
network participants (miners) using votes. Boolberry gives a fixed
percentage to the CryptoNote founders.
Wallet address aliasing: any wallet can be linked with
symbolic name via special type extra record in coinbase. Block chain
will control registered names uniqueness.
More rational emission curve
Boolberry and SuperNetwork
SuperNET
Planned NXT features will be implemented into the core of BTCD. BTCD
will be an entire platform, and act as a cryptocurrency supernetwork and
the following NXT features will be integrated:
Wild Keccak PoW Algorithm
Wild Keccak is a Keccak hybrid which uses block chain data as a
scratchpad. After each Keccak round, pseudo-randomly addressed data
[state vector used as addresses] data is taken from scratchpad and XORed
with state. Calculating each block PoW usually hits about 1100 randomly
addressed reading of blocks by 32 bytes.
Untraceable payments
The ordinary digital signature (e.g. (EC)DSA, Schnorr, etc…)
verification process involves the public key of the signer. It is a
necessary condition, because the signature actually proves that the
author possesses the corresponding secret key. But it is not always a
sufficient condition. Ring signature is a more sophisticated scheme, which in fact
may demand several different public keys for verification. In the case
of ring signature, we have a group of individuals, each with their own
secret and public key. The statement proved by ring signatures is that
the signer of a given message is a member of the group. The main
distinction with the ordinary digital signature schemes is that the
signer signer needs a single secret key, but a verifier cannot establish
the exact identity of the signer. Therefore, if you encounter a ring
signature with the public keys of Alice, Bob and Carol, you can only
claim that one of these individuals was the signer but you will not be
able to pinpoint him or her.
This concept can be used to make digital transactions sent to the
network untreaceable by using the public keys of other members in the
ring signature one will apply to the transaction. This approach proves
that the creator of the transaction is eligible to spend the amount
specified in the transaction but his identity will be indistinguishable
from the users whose public keys he used in his ring signatures.
It should be noted that foreign transactions do not restrict you from
spending your own money. Your public key may appear in dozens of
others’ ring signatures but only as a muddling factor (even if you
already used the corresponding secret key for signing your own
transaction). Moreover, if two users create ring signatures with the
same set of public keys, the signatures will be different (unless they
use the same private key).
Unlinkable transactions
Normally, when you post your public address, anyone can check all
your incoming transactions even if they are hidden behind a ring
signature. To avoid linking you can create hundreds of keys and send
them to your payers privately, but that deprives you of the convenience
of having a single public address.
CryptoNote solves this dilemma by an automatic creation of multiple
unique one-time keys, derived from the single public key, for each p2p
payment. The solution lies in a clever modification of theDiffie-Hellman exchange protocol.
Originally it allows two parties to produce a common secret key derived
from their public keys. In our version the sender uses the receiver’s
public address and his own random data to compute a one-time key for the
payment.
The sender can produce only the public part of the key, whereas only
the receiver can compute the private part; hence the receiver is the
only one who can release the funds after the transaction is committed.
He only needs to perform a single-formula check on each transactions to
establish if it belongs to him. This process involves his private key,
therefore no third party can perform this check and discover the link
between the one-time key generated by the sender and the receiver’s
unique public address.
An important part of our protocol is usage of random data by the
sender. It always results in a different one-time key even if the sender
and the receiver both remain the same for all transactions (that is why
the key is called “one-time”). Moreover, even if they are both the same
person, all the one-time keys will also be absolutely unique.
Double-spending proof
Fully anonymous signatures would allow spending the same funds many
times which, of course, is incompatible with any payment system’s
principles. The problem can be fixed as follows.
A ring signature is actually a class of crypto-algorithms with different
features. The one CryptoNote uses is the modified version of the “Traceable ring signature”
[1]. In fact we transformed traceability into linkability. This
property restricts a signer’s anonymity as follows: if he creates more
than one ring signature using the same private key (the set of foreign
public keys is irrelevant), these signatures will be linked together
which indicates a double-spending attempt.
To support linkability CryptoNote introduced a special marker being created by a user while signing, which we called a key image.
It is the value of a cryptographic one-way function of the secret key,
so in math terms it is actually an image of this key. One-wayness means
that given only the key image it is impossible to recover the private
key. On the other hand, it is computationally impossible to find a
collision (two different private keys, which have the same image). Using
any formula, except for the specified one, will result in an
unverifiable signature. All things considered, the key image is
unavoidable, unambiguous and yet an anonymous marker of the private key.
All users keep the list of the used key images (compared with the
history of all valid transactions it requires an insignificant amount of
storage) and immediately reject any new ring signature with a duplicate
key image. It will not identify the misbehaving user, but it does
prevent any double-spending attempts, caused by malicious intentions or
software errors.
Blockchain analysis resistance
There are many academic papers dedicated to the analysis of the
Bitcoin’s blockchain. Their authors trace the money flow, identify the
owners of coins, determine wallet balances and so on. The ability to
make such analysis is due to the fact that all the transfers between
addresses are transparent: every input in a transaction refers to a
unique output. Moreover, users often re-use their old addresses,
receiving and sending coins from them many times, which simplifies the
analyst’s work. It happens unintentionally: if you have a public address
(for example, for donations), you are sure to use this address in many
inputs and transactions.
CryptoNote is designed to mitigate the risks associated with key
re-usage and one-input-to-one-output tracing. Every address for a
payment is a unique one-time key, derived from both the sender’s and the
recipient’s data. It can appear twice with a probability of a 256-bit
hash collision. As soon as you use a ring signature in your input, it
entails the uncertainty: which output has just been spent?
Trying to draw a graph with addresses in the vertices and
transactions on the edges, one will get a tree: a graph without any
cycles (because no key/address was used twice). Moreover, there are
billions of possible graphs, since every ring signature produces
ambiguity. Thus, you can’t be certain from which possible sender the
transaction-edge comes to the address-vertice. Depending on the size of
the ring you will guess from “one out of two” to “one out of a
thousand”. Every next transaction increases the entropy and creates
additional obstacles for an analyst.
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