Aventus (AVT) fair, secure, and transparent ticketing industry.

  • About Aventus

    Aventus is a fair, secure, and transparent blockchain-based event ticketing solution that practically eliminates fraud and unregulated touting. Organisers can create, manage and promote their events and tickets with dramatically reduced platform costs, and can set price controls and receive commissions on secondary market sales.

    How it works

    1.Create Your Event 

    Sign up and create your event for a fraction of the fees charged on other online ticketing hubs. Create and issue your tickets, which can be anything from drink vouchers to early bird entry. 

    2.Set Your Own Ticket Market Standards 

    Choose if you want your tickets to be resold and in what price range, and even set a fee that you earn from every resale! No one can scam the system, so no more counterfeits and unfair, unregulated ticket black markets ruining your brand name. 

    3.Promote your event

    Leverage blockchain-based micro-payments to create complex reward schemes for ticket buyers in exchange for generating you more ticket sales, drastically decreasing your promotional spend. 

    4.Sell and Verify Tickets with minimal Fees 

    Sell tickets for a fraction of the cost on the blockchain. At the event, allow your staff to easily asecurely verify tickets at the door and the bar with just our app and a smartphone.

    The Aventus ecosystem.

    An Ethereum account management platform where users with minimal crypto-currency knowledge can have their accounts, funds, and transactions managed on their behalf.

     A fiat to AVT conversion mechanism so that users can buy tickets easily, and so event organisers and app developers can cash out quickly if necessary to avoid currency risk. This will be done through a third party payment processor such as Uphold or MetalPay. 

     A ticket and ID validation service where attendees’ faces will be scanned and compared to photos uploaded at point of purchase using machine vision. This will reduce entry fraud at events and allow organisers to track the performance of bouncers.  

    Template user interfaces and integration tools that further lowers the barrier to entry to creating a customised ticketing interface for event organisers (e.g. a football club) or promoters (e.g. an influencer).

     Others worth mentioning include in-event advertising tools and reputation calculations for promoters with respect to sales generated in previous, similar events.

    More services will be added over time depending on demand. Although developers
    using these services will incur an additional cost, such tools will make building ticketing
    applications significantly easier especially with respect to onboarding mainstream users.

    AventCoin (AVT) - The Aventus Token


    The Aventus protocol token AventCoin is essential for aligning the economic incentives of
    participants such that the problems in section 1 are solved, and for ensuring that minimal
    fraud occurs in the system. Its main purposes are:
    1. To provide an incentive layer to enable self-regulation of the Aventus
    Protocol. This refers to stake-weighted voting mechanisms (further explained in
    section 3.1) for the Aventus Community to determine:
    a) Legitimate apps/DApps using the Aventus Protocol (section 3.1.1) so
    that event organisers and ticket buyers are not taken advantage of.
    b) Legitimate events on the Aventus Protocol (section 3.1.2) so that apps/Dapps
    do not lose users by selling tickets for fraudulent tickets.
    c) Aventus Protocol algorithm parameters that determine important fees in
    the system such as the event-creation fee (section 3.1.3), so that the protocol
    can constantly evolve to remain competitive.
    2. To reward early adopters of the Aventus Protocol, thereby enabling it to benefit
    from network effects. Network effects apply to the Aventus Protocol since as the
    number of events using it grows, the greater value it has to third party applications.


    There are four primary use cases for AVT:

     Event hosting: event organisers must purchase AVT to pay the event-creation
    price. This cost will be proportional to the number of events deemed fraudulent in
    the protocol. It will not be affected by the volatility of AVT by accounting for the
    fiat currency exchange rate. In the initial phase of using the Aventus Protocol, at the
    end of a successful event, AVT from the early-user incentive pool will be distributed
    amongst all participants in the event to reward early-event host-adopters, promoters
    and secondary market facilitators.

     Ticket sales: although tickets to an event on the Aventus Protocol must be purchased
    in ETH, AVT or any other ERC-20 compliant crypto currency, the volatility
    associated with crypto-currencies will be mitigated. Ticket prices will be denominated
    in fiat currency and use a market-feed oracle to calculate AVT prices at the
    time of purchase. Event organisers and promoters are free to cash out their cryptocurrency
    from ticket sales or commissions, at their convenience, to avoid holding it
    for unnecessary periods of time.

    Community stake: events can be reported as being suspected of being fictitious
    or fraudulent through a mechanism which involves putting up a deposit of AVT. If
    the deposit is matched by the organiser of the (purported) event, a stake-weighted
    vote would be initiated, in which any stake-holder can agree or not (elaborated upon
    in section 3.1 below). Platforms building on the Aventus Protocol would have an
    incentive not to sell fictitious or fraudulent tickets to their users, thus giving them
    an incentive to hold AVT for voting and future event-creation. Applications making
    sales on the protocol go through a similar process of being validated by the network
    so that we can remove the current problems in the industry of fraudulent resellers.

    Matching: Tickets sold on the Aventus Protocol in the secondary market must be
    matched with buyers who have previously registered a firm intent in their purchase
    at their listed prices. To list a ticket for resale a user will also have to be able to pay
    the secondary market sale fee in AVT. Matching is on chain calculation that Aventus
    Protocol users can run to pseudo-randomly match buyers and sellers and receive the
    secondary market sale fees for doing so. This ensures that sellers do not know who
    they are selling to to prevent off chain monetary transactions taking place for the
    transfer of a ticket and then a transaction in the system merely being logged which
    adheres to the restrictions.

    White Paper:





    Info dec:




  • Aventus (AVT) Case Study: Sports Daily and Spotify as Third Party Ticket Distributors

    What if…

    What if your favourite blogger didn’t just write features about your preferred sports teams but also had the ability to sell tickets for their upcoming events? If they could, then not only would you be able to get all of your daily information about your favourite teams, but you would also be able to buy tickets to see them play. You would not have to open a new tab, find TicketMaster, and look for tickets; they would be right there, in a widget, being sold on the blog!

    At Aventus, one of our primary objectives is to enable this type of third party integration to happen as frictionlessly as possible for anyone from a social influencer, to a blog, to a streaming platform, to a general event listing site.

    Why this matters

    One of the biggest problems in ticketing is unsold inventory; in particular, sporting events suffer considerably from this phenomenon. The ex-CEO of TicketMaster, Sean Moriarty, estimated that 35% of ticketing inventory on TicketMaster goes unsold, and when you ask fans why they did not attend, their main reason is that they did not know about the event.

    The primary reason for this is the siloed nature of the ticketing industry; a promoter is in charge of filling the full allocation, and finds sub-promoters, ticketing agents, and other entities to fill portions of this allocation. Hence, the reach of the event is limited by the audiences of the promoters, sub promoters, and ticketing agencies that the event organisers know to begin with.

    Nowadays, if an entity like Spotify wishes to sell some of Adele’s ticketing inventory, an affiliate agreement must be crafted between Spotify and an entity owning the allocation in question, which specifies the rules of sale amongst other contractual requirements. It is a fairly long process, and most ticketing agents and promoters still use Excel spreadsheets to track allocations!

    Enter Aventus and the blockchain.

    With the Aventus protocol, we aim to de-silo the ticketing industry and bring the full ticketing inventory to the blockchain. The core idea: since we eliminate black markets and allow event organisers to control the entirety of the ticketing lifecycle, those contractual clauses in the affiliate programmes live as rules in smart contracts in the Aventus protocol that cannot be broken. Further, via the creation of a decentralised bidding process on portions of the ticketing inventory on the blockchain, we allow this ticket distribution process to occur with ease. No more 6 month negotiations; affiliates can bid, be approved, and start selling tickets in a matter of minutes.

    Now, events will not be limited in reach by the promoters and sub-promoters they know; now, anyone who has a target audience that overlaps with the event can bid on inventory, sell tickets, and allow the event organiser to expand his possible reach! This results in less unsold inventory, a more diverse attending audience, and more prospective customers for the event organiser.

    How would it work?

    For the purpose of this post we’ve decided to use The Sports Daily as our sporting events use case and a platform that needs no introduction, Spotify, as our concert & music festival use case.

    The Sports Daily is a blogging platform that writes about various sports features (hence the name, The Sports Daily). The night before Sports Daily publishes an article hyping the Connor McGregor/Floyd Mayweather fight for example, they can either use the Aventus services API or the Aventus inventory dashboard to bid on a portion of ticketing inventory for the fight. Once approved, they can place the white-label Aventus ticket sale widget next to the article, and allow their readers to frictionlessly buy tickets to the event.

    Not only does this make life easier for consumers, but it also opens up an entirely new revenue stream to Sports Daily.

    For Spotify for example, the integration could be even more interesting, and very much data-driven. Since an anonymous ticket purchase history is available on the blockchain, if consumers give Spotify (in exchange for some sort of reward) access to their purchase history, Spotify can now targetedly place ticket-buy buttons next to songs or artists that their consumers are listening to. This is beneficial for Spotify in terms of a new revenue stream, but also for their consumers as they will now get targeted ads that add value to their listening experience.

    To stay up-to-date with Aventus as we bring our solution to the event ticketing industry follow us on Twitter, join our Slack Channel, or join our mailing list!

  • A Message To the Aventus Community About Security Concerns

    This is a message from Annika Monari and Alan Vey, the founders and directors of Aventus. We are writing to address the Aventus Presale Phishing Attempt, which harmed us and our community as a whole.

    As many of you know, last night at around 22:20 BST a login to our Mailchimp account from IP: in Bucharest, Romania occurred, and a fraudulent email was sent out about an illegitimate Aventus Presale, phishing for contributions to a hacker’s address. Disgracefully, the hacker was able to obtain about 39 ETH at the point of writing from around 15 of our community members (Note some of these transactions are likely the hackers themselves). The hackers had access to our mailing list, but the only sensitive information they got was our community’s email addresses. One of our employee’s accounts was not sufficiently protected and was compromised, which is how the hackers managed to access MailChimp. Given the strict internal security policy at Aventus, the individual had restricted access to everything, which is why the situation was limited to MailChimp and could be quickly rectified by us within 20 minutes.

    By 22:40, we had handled the situation and locked out the hackers. By then we had been in touch with Mailchimp and changed all of our passwords and 2FA settings on all other Aventus accounts. We sent out a follow up email that stated that the previous email was a scam to our entire mailing list warning them not to contribute funds, and we answered every email and Slack question that came in and confirmed that the scam was indeed a scam. We had also deleted the compromised employee’s access to all Aventus accounts. We can confirm that all other sensitive information and Aventus accounts remained completely secure and untouched by the hack.

    Our community members did an excellent job of mitigating the damage done from the attack; from 22:20, our community took the lead. We received numerous emails and warnings on Slack about the phishing attempt in our #link-duedilligence channel, and people already started working to track down the perpetrators. We would like to thank you all so much for helping us and standing by us when times got tough; we are immensely grateful for the actions of our growing community.

    Alan and Annika, the founders of Aventus, are taking full responsibility for what has happened. We are extremely sorry for the pain we have caused some of you. We value our community above everything so to us there is nothing worse than some of our loyal members and newer crypto enthusiasts being taken advantage of by malicious and cowardly actions such as those last night. We will be restoring all stolen funds in this recent scam attempt provided you can prove being in the community for a while and are not part of the hack and the transaction was sent before the release of the second email confirming the SPAM (about a 30 min window); we have already been in direct contact with some of the individuals who lost funds, but if you have not been in touch yet please email us at [email protected] with information about yourself and your transactions so we can refund your loss.

    This is a huge lesson to us all. We have been working around the clock to ensure a new, extremely high standard of security, which we will outline below:

    • None of Aventus’ email accounts, social media accounts, or servers were compromised; only Mailchimp, and that is how they were able to send an email looking like “[email protected]”. We have deleted our Mailchimp account and created a new one from scratch with a password adhering to the highest security standards stored offline, 2FA and only Alan and Annika have access to it.
    • Since email, or more formally SMTP does not validate the “from” address, it is possible for anyone to send an email looking like it came from any address, such as [email protected] or even [email protected] Therefore, we will be accompanying every official email with 3 sources of proof; (1) a tweet confirming the email; (2) a post on our blog, and (3) a Youtube video linked in the email, where Alan or Annika will read out a random string of characters contained at the top of every email. We will NEVER ask for any contributions via email.
    • Our token sale address will never be sent via email. We will be releasing it today via 5 sources of proof (some of these we have been mentioning for weeks now):  (1) You will be able to look up Aventus.eth on etherscan.io which uses the Ethereum Naming Service for complete security. This will be our token sale address;  (2) in a tweet on our official Twitter account;  (3) #announcement channel in Slack;  (4) a video recording of us reading our the address;  (5) A blog post.  Please do not send any funds to any address other than after you have cross-checked at least 3 of these sources of truth.
    • We have rechecked the MetaCert config on our Slack team and will be using it to monitor all phishing attempts. Tomorrow, on Monday September 4th we will also be disabling all communication on our Slack team; only the #announcement channel will be accessible and this will only contain official statements from Alan and Annika. To get in touch please email [email protected] or tweet us @AventusSystems.
    • We have changed all passwords and increased their difficulty 10 fold. We also have 2 factor authentication enabled on every account possible. Until the token sale ends, no account sharing, even through password managers, will occur. We have even higher security protocols internally for our employees to adhere to, which of course we will not be disclosing publicly.

    Thank you again, all of you, for your continued support and commitment in helping us put out the fire and manage our community and the repercussions of this attack. We are very fortunate that you are still standing by us, despite what has happened. Lets continue to work together to make Aventus a huge success and a much needed change in the traditional ticketing industry.

    We have plenty of announcements coming today, tomorrow, and before the token sale commences on the 6th September; we cannot wait for you guys to see what’s in store.

    Sincerely, Annika Monari and Alan Vey Directors and Founders of Aventus

  • How to Participate in the Aventus Token Sale

    Hi all! As we approach the final days before our token sale we have put together a guide for how to contribute, expected gas limits, and approximate block numbers.

    The official contribution guide is here, but please read the information below first.

    We advise that you use MyEtherWallet for your contributions, or any of the wallets listed here.

    Token Sale Structure

    • From 5 September 2017, 12:00pm UTC to 6 September 2017, 12:00pm UTC the whitelist submission period occurs. During this time, only participants registered on the Aventus whitelist will be able to contribute Ether. All other transactions will be rejected.
    • From 6 September 2017 12:00pm UTC to 13 September 2017 12:00pm UTC, the public token sale occurs. During this time, any participants will be able to contribute to the sale. During the public sale, there will be at minimum 5,000 ETH.

    Important information:

    • All information, contribution instructions, T&Cs etc. will be at https://sale.aventus.io.
    • You are not buying a security, you are buying a utility token for the Aventus Protocol and associated network. As a purchaser of AVT, you are not making an investment of capital — you are purchasing AVT to obtain the bundle of rights associated with the token, including the use of the Aventus Protocol.
    • The approximate block number of the public token sale is block #4,244,327.
    • The gas amount limit we suggest to put in your transactions is 110,000. It will definitely cost less, but we suggest you put that limit to be sure your transaction gets in.
    • Please DO NOT SEND ANY ETHER TO ANY ETHEREUM ADDRESS SENT IN AN EMAIL. We will NOT email you any addresses asking for contributions.

    Token Sale Address

    Please note: if you send any Ether to the address below it means you have agreed to our terms and conditions.

    The token sale address is: 0x8b7B6C61238088593BF75eEC8FBF58D0a615d30c.

    The token sale address will also be presented in the following 4 ways. ALWAYS CROSS CHECK MULTIPLE SOURCES BEFORE SENDING ANY FUNDS.

    We are very excited for our token sale starting on September 6. If you have any questions about the information above, please give us a shout on Slack; our team is working around the clock to ensure a smooth sale with the maximum security, and is answering all questions as quickly as possible.

  • Aventus (AVT)  Weekly Update Exchange Listings,Product Development & More

    This is our second update in our weekly update series about our progress in building our business and product at Aventus. Over the last week, progress has been made on the following fronts:

    • Exchange listings
    • Hiring
    • Press
    • Product Development

    Exchange Listings and Price Dip

    We feel like its starting to sound like a broken record, and we apologise for the inconvenience and irritation this has caused; listings take time, especially given the current market and legal conditions. We explored larger options instead of pursuing smaller exchanges, but with the recent regulatory changes and overall market sentiment it has not been as quick of a process as we would have hoped. Our legal team is working hard to finalise these deals and assure all parties of the extensive audit we had done pre-token sale.

    Because of the delay in these listings, we have altered our strategy and decided to start pursuing smaller exchanges. We can assure you that there will be a new listing next week, albeit most likely one of the smaller exchanges.

    We also wanted to note on the price dip in AVT. Opening in a down market is not the only reason for the situation; unfortunately, we spent a lot of time and effort marketing to China, and as most of you know in the midst of our token sale their regulatory landscape changed. Hence, to abide to the new laws, we had some Chinese participants that had to dump their tokens immediately — in the region of 10,000 ETH was from China. This is the reason for the large and immediate sell volume seen on EtherDelta.

    Hiring, Community

    We have made significant strides in acquiring new team members, and even finalised the lease for a new office space in London (we move on October 2 and will be sharing photos then!). We are going to be doing a proper announcement of our new employees over the next couple of weeks (their start dates are not till at least mid-October), but we can confirm now that we have hired two new engineers and, and have shortlisted both a head of communications and community manager.

    Please note; it is worth mentioning that we will be moving off of Slack this week due to the constant spam from scammers using Slackbot and direct messaging. We apologise for any inconvenience caused, and will be moving over to a new platform more suited to our use-case by Thursday.


    If you did not see our announcements last week, we will present them here as well.

    Product Development

    We have been working closely with our first partner, Townsend Music, on rolling out more features in our Blockchain as Persistance (BaP). We even have one off-chain version of a product for inventory management in beta! Townsend Music is currently using it, and it is connected to BaP. We will be releasing more details soon, but for now we are staying quiet whilst we conduct more tests, iterate based on feedback, and roll out more functionality.

    We are moving very quickly, have a product in beta, and are rapidly developing out our product line. We have a lot up our sleeve but thought to give you guys some brief information in the mean time so you can get excited.

    To stay up to date with Aventus as we develop the business, the protocol and our overall product offering, please join our mailing list, join our Slack, or follow us on Twitter.

  • Aventus Weekly Update - Exchange Listing, Voting Module Release , New Team Member & More

    Hey guys! We have some big announcements in today’s weekly update. There have been a lot of questions in our community this past week and we hope to answer a lot of them today. Furthermore, a subsequent Q&A video with Alan and Annika will be released on our Aventus YouTube channel shortly. This is what we’re covering today:

    • Voting Module Release
    • Community Platforms
    • Exchange listing
    • AVT review from The Crypto Lark
    • New Team Member

    Voting Module Release

    We will be releasing our voting module on the Rinkeby Ethereum Testnet today! The wait is over — thank you for your patience. We will announce when it is live across our social platform and you can then access it at: vote.aventus.io

    You can read all about our Voting Module in a previous blog post : Aventus Protocol (Part 1): Deep Dive on Voting

    Please test the module out extensively and if you enquire any bugs or problems with the blockchain based protocol, please report them according to the rules you can find here: Aventus Protocol Bug Bounty — Rewards up to $10,000!

    Significantly, the mainnet release is ready to go! However, due to the unexpected cancellation of the Bitcoin fork, we are not yet prepared from a PR and marketing point of view to release it. Therefore, it will be delayed until early next week. We know that many of you would like us to release stuff as soon as it is ready, but this is not necessarily that beneficial to you. Creating a buzz around a release will increase the value of AVT and give the Aventus brand more exposure — both of which we think are very important. We know what we’re doing and we have partnered with a reputable, global PR company, so please be patient. We are constantly working on the best solutions and maximising the results for our community!

    Community Platforms

    This week we opened our new Telegram group, which was highly requested from our community members. You can join the conversation HERE. Please also follow our Aventus channel on Telegram.

    Additionally, we are also very excited to reveal the launch of our official Facebook page. You can find it HERE. Be sure to check it out and give us a like.

    We are also thrilled to announce that our Twitter followers almost doubled in 24 hours and we now have over 30k on the platform! A huge thank you to our community for all of your support. Twitter: @AventusSystems

    Exchange Listing

    This week we have had a lot of questions regarding when we will be listed on the next exchange. We are in the process of setting up new listings for you guys, however this process isn’t instantaneous. All legal agreements need to be finalised and then it is up to the exchanges as to the exact day they will list us on their sites. We are legally not allowed to comment or announce which exchange we will be on until the agreement has been finalised. The best thing to do is to follow the various exchanges on Twitter (and us of course) and as soon as we go live it will be posted. Please be patient.

    AVT review from The Crypto Lark

    Thanks again to The Cryto Lark for his excellent review of AVT in his most recent YouTube video. If you haven’t watched it yet, then you can view it below.

    It is great to get such positive feedback from 3rd parties. We are always interested in working with people from our community and influencers in the industry. Please get in touch if you would like to discuss a project and see how a partnership could benefit both of us.

    New Team Member

    We have a new team member joining us next week. We are extremely excited about having him on-board the team. We will be releasing a Q&A with him in next week’s blog. All we can say for now is that he is a highly experienced developer joining the blockchain team and will be an amazing asset to Aventus.

    To stay up to date with Aventus, please join our mailing list, the discussion on Discord, or follow us on Twitter.

  • Aventus Weekly Update - Mainnet Release, YouTube Q&A & More

    Hello everyone. As most of you already know, we are posting the blog a day early this week. But the earlier, the better! This week’s blog is a little bit different, because we wanted to take the time to discuss our hiring strategy and really emphasize the importance of hiring the right team. There are some updates as well. This is what’s being covered today:

    • Hiring the right team
    • New team member! Meet Bob, our blockchain developer
    • YouTube Q&A with Alan and Annika
    • Telegram
    • Mainnet Release

    Hiring the right team

    We have put a lot of thought into hiring the best people for Aventus and have had a lot of success with our model, which will become apparent once we publicise our full team. The first thing we do is have an informal meeting with a potential candidate (once we have sorted based on CV), this is typically in the form of a coffee or beer. This gives us a chance to figure out if we feel we get on with the candidate and could work with them effectively. If we are happy we give the candidate a task to research and make and try their hand at implementing. Once they have finished to a satisfactory level, we invite them in to the office and start off by running through the task and diving in to the technical details required for the position. Straight after than we have a discussion around working process and go though past, present and future for the candidate and the why to the various career choices along with any other details we feel need further clarification. After that we introduce the candidate to the existing team and make sure there are no conflicts in personality or approach.

    Our approach is very much about who people are and their attitudes before considering individual skill sets. We would rather have a humble, eager to learn candidate than a superstar who is particularly arrogant in their field, since we feel this will lead to a better team atmosphere where everyone can improve much faster, ultimately resulting in a better product. Don’t get us wrong, a superstar in their field with a great attitude is the ideal candidate and we have been told by such candidates that our process is what set us aside from their other offers and ultimately made them join us. As always we are looking to improve and refine our model so please do give us your thoughts on the process.

    New team member! Meet Bob, our Blockchain Backend Developer

    Babashola King, our newest blockchain engineer.

    Can you first introduce yourself please; tell us a bit about you? Maybe a fun fact we wouldn’t expect?

    I am Babashola King but friends call me Bob. I have been in the IT industry for many years now in some development capacity. I am always looking for a new challenge to keep be entuse. I am obsessed with Latin Dancing (mainly Salsa/Kizomba).

    What is it that you do at Aventus? How did you hear about the company and what made you apply for your role?

    Joined Aventus to help build/progress the fantastic effort already invested in the blockchain backend development.

    You have years of experience in the industry. Tell us a bit about your background?

    I have mainly worked within the fintech industry. Spent 10 years with a hedge fund (Leo Fund Managers) building proprietary Portfolio management systems. My skillset has evolved over the years depending on the set tasks, but it was predominantly in Java development I spent the best years.

    When did you first hear and start learning about blockchain? What is the most interesting thing about it to you?

    I was busy seeking another venture to get into and then I was offered the opportunity to get involved at the root level at Aventus. I jumped at the chance to learn with these clever colleagues. Blockchain/Ethereum just seems to be a HUGE innovation at the moment and a chance to get involve with it was too huge to pass on.

    What do you hope to achieve at Aventus? What are you particularly excited to work on?

    I sincerely hope to become very critical and contribute where possible as quickly as possible. I am so excited to gain the necessary Ethereum blockchain development knowledge to be progressive at Aventus and to contribute to the community where possible.

    How can the community get more involved with what you are doing at Aventus?

    Ultimately with increase knowledge of the blockchain, I will be able to create components that can better improve the standards and approach adopted in the community.

    Why do you think Aventus is relevant for society, and specifically for ticketing?

    Aventus group as a whole is paying attention to the advancement of the generic open source availability and progression. The thought process is cantered around improvement and simplification of the available standards around Ethereum blockchain. Their knowledge around the ticketing process seems so vast and continuously reviewed with view to improvement and security.

    What are your hobbies?

    Salsa / Kizomba Dancing

    YouTube Q&A with Alan and Annika

    Last week we posted on our Facebook page requesting our community to ask us any questions, which we would answer in a YouTube Q&A. There were some great questions and Alan and Annika really enjoyed hearing what you guys were interested in. Below is the teaser video that was released on Monday. The entire Q&A will be up on Thursday on your YouTube page, plus we’ll post it across our social channels.


    We have been on Telegram a week now and are missing some of you! Don’t forget to join the group via THIS invite link and join the conversation. Our Head of Communications, Robyn, is always online and can answer any questions you may have. The rest of the team, including Alan and Annika, pop in and out through the day. Come say hi!

    Mainnet Release

    We announced in last week’s update that we would be releasing our voting module on the Rinkeby Ethereum Testnet. This is now up and multiple iterations of the contracts have been deployed and tested on Rinkeby.

    Regarding the mainnet release, it will also be going up this week as promised. We expect it to go up Thursday, however please do not take that as final confirmation. There is a good chance we will take an extra day to run the testing suite before publicising it. The voting UI has been tested for the past 10 days in private beta and will be released at the same time on https://vote.aventus.io.

    To stay up to date with Aventus, please join our mailing list, the discussion on Telegram, or follow us on Twitter and Facebook.

  • Weekly Update #11: Update on Exchange Listings, New Hire and Marketing Strategies

    Hello everyone. This week we are introducing our new blockchain engineer, Vincent, we will also be giving you an update on the exchange listings and discussing our YouTube video, which will be out tomorrow.

    • Exchange listings
    • Meet Vincent! Our new blockchain engineer
    • YouTube Teaser

    Exchange Listings

    We get asked daily when we will next be listed on a new exchange. The answer is soon. As we have said multiple times, we are going the extra mile legally to ensure everything is up to scratch and that Aventus and AVT holders have a long and prosperous future.

    A short update though: The final steps are completed with the regulators. Alan and Annika will be travelling to Jersey next week Tuesday to wrap things up. Thereafter, the foundation will be ready to execute outstanding exchange listing agreements. We are not giving a time frame, however this has been a long process (longer than anticipated) and we are nearing the end.

    Meet Vincent! Our new blockchain engineer

    Can you first introduce yourself please, tell us a bit about you? Maybe a fun fact we wouldn’t expect?

    I studied engineering (control) at University of Cambridge, but I’ve been working most of my life in software development. Recently, I’ve been learning ways to teach kids programming.

    What is it that you do at Aventus? How did you hear about the company and what made you apply for your role?

    I’m a blockchain developer at Aventus. I applied through a recruiter who was looking for experienced C++ developers. I basically jumped into it when I was told about this opportunity to build a blockchain solution from the ground up, as I was very excited to join a very dynamic, game-changing industry.

    You have years of experience in the industry. Tell us a bit about your background?

    I started as an industrial (automation) enginee and have worked for 20+ years in software development in various industries. For the past 10+ years, I have mostly developed codes in various enterprise systems in finance (electronic market-making and high-frequency trading), telecommunication and automated manufacturing in high-throughput, low-latency and distributed environments using C++.

    When did you first hear and start learning about blockchain? What is the most interesting thing about it to you?

    I tried mining bitcoin and some altcoins a few years ago, but never got around to doing it the “right” way. However, the exercise strengthened my interest in blockchain. In particular, I like the programmability aspect of the smart contract in blockchain.

    What do you hope to achieve at Aventus? What are you particularly excited to work on?

    I want to help build secure, cost-efficient systems to reduce the cost of ticket sales transactions. I am particularly excited to work on ways to optimize secure decentralized apps in terms of transaction cost and speed of processing.

    How can the community get more involved with what you are doing at Aventus?

    Send some Ethers to a bounty account for 6 months. The bounty account gets to keep any appreciated value, which is used to reward users for testing and bug-finding of Aventus system. Donors may redeem up to the maximum donated Ethers or a certain portion from the remaining pool, whichever is lower.

    Why do you think Aventus is relevant for society, and specifically for ticketing?

    Aventus aims to reduce friction and transaction costs using blockchain. The know-how and experience can be deployed to the wider audience in the blockchain industry in general and the ticketing industry in particular.

    What are your hobbies?

    I like table-tennis and badminton.

    YouTube Video

    Tomorrow we will be releasing our weekly YouTube video. This week our
    Head of Communications, Robyn, briefly sat down and went through our
    general marketing strategies, social media strategies and PR. So be sure
    to watch that tomorrow HERE.

    To stay up to date with Aventus, please join our mailing list, the discussion on Telegram & Discord, or follow us on Twitter &Facebook.

  • Aventus (AVT) - Weekly Update #13: The Price of ETH, New Website, Marketing and PR Update, and more

    Hello guys. We have some interesting news for you this week, as we’re half way through December leading up to the new year. Lots happening here at Aventus and as always we’d like to share it with you. Here’s what we will be covering today:

    • Aventus Foundation: Where the foundation is currently at & what this means for exchange listings
    • The price of ETH: What does this mean for Aventus
    • New website: Screenshots and hopeful release date
    • Marketing and PR update: 2018 marketing plans and when to expect a big PR push
    • New hire: Front-end engineer

    Aventus Foundation

    Alan and Annika recently travelled to Jersey in the Channel Islands to finalise the Aventus Protocol Foundation, which is registered there. Last week gave you an update on this and briefly wanted to state that everything is now completely out of Aventus’s hands. We are now just waiting for two more exchanges to list us. For legal reasons we cannot say more, but more news will hopefully follow shortly. Be sure to keep checking out Twitter, as we post up-to-date information on there immediately.

    The Price of ETH

    As all in the crypto currency space know, the price of ETH has skyrocketed. There is a lot of speculation as to why this has happened, considering it has risen by a staggering 2300% this year. There are many trying to pinpoint the exact reason for this increase, however it is unsure which exact one is truly the main factor.

    But what has this meant for Aventus and did we act on it?

    The answer to that is straightforward: we decided to exchange 20,000 ETH into US dollars. This means that we are now financially protected from market downturn in the future and have increased the security of our business for all involved.

    New Website

    We have announced our new website in our Telegram and Discord groups, however we wanted to officially confirm that a new site will be going live in the very near future. We are aiming for the end of the year to start fresh in 2018, but as you know with any software project, we cannot set a hard deadline as unpredictable developments can result in variable time delays. The new site will include a highly requested roadmap, short bios and photos of the entire team and more. We’re very excited for you all to see it and thought we’d post a few screenshots below. They are teasers and a few details may still change.

    Marketing and PR Update

    There were a few comments in our community recently about marketing and PR. We felt is necessary to comment again on this topic. A short and medium-term marketing plan has been developed internally, planned to start in January 2018, that will centre around building our open standard for ticket exchange with as much feedback and input from industry participants as possible. This marketing strategy includes targeted and frequent press in both crypto and mainstream/ticketing media, influencer marketing, events and hackathons, and more. More on this will follow, along with an announcement of who our PR agency is and the role they will play in executing our marketing vision. For now, we are staying quiet and are focused on meticulous planning.

    New Hire

    One of our two new front-end engineers will be joining us next week. Both had lengthy notice periods, but we are super excited to have them join us soon. We will be posting the interview with our first joiner of the front-end team next week.

    P.s. He is another Andy! Making it a total of three in the Aventus team, and a difficult game of who’s-who in the office.

    To stay up to date with Aventus, please join our mailing list, the discussion on Telegram & Discord, or follow us on Twitter & Facebook.

  • Working with Strings in Solidity

    This is the first in a series of blogs we’re going to bring to you directly from the trenches, going into some of the nitty-gritty technical detail of some of the things we’re doing with the Protocol at the moment.

    Today’s article comes from Alex Pinto, a recent addition to our blockchain engineering team who’s been spending the past few weeks getting up to speed on using Solidity, and will take us through some of the challenges and particularities of the language.

    Today I give you a post about programming for the Ethereum blockchain using the Solidity language. I won’t follow any plan in doing this: my objective is only to write about my obstacles in learning this language and the practical difficulties I encounter in my daily work.

    I want the freedom to write about any topic without having first to introduce preliminary material, as I’d have to do if I were writing a textbook. If you notice me talking about things I have not explained before, that is by design. Leave me a comment below and I’ll come back to them in a later post.

    Basic access

    Today, I want to talk about strings in Solidity. Solidity is, at first, similar in syntax to Javascript and other C-like languages. Because of that, it is easy for a newcomer with a grounding in one of several common and widespread languages to get a quick grasp of what a Solidity program does. Nevertheless, Solidity is mighty in the proverbial details that hide unforeseen difficulties. That is the case of the type string and the related type bytes.

    Both of these are dynamic array types, which means that they can store data of an arbitrary size. Each element of a variable of type bytes is, unsurprisingly, a single byte. Each element of a variable of type string is a character of the string. So far so good, but the initial looks are deceiving. One who comes from other languages might expect the string type to provide several useful functions, like:

    • determining the string’s length
    • reading or changing the character at a given location in the string
    • joining two strings
    • extracting part of a string

    Bad news: Solidity’s string does none of this! If we need any of the above, we have to do it manually.

    So, let’s explore some of these difficulties and see what we can do about them. I open Remix and type the following code in a new file called string.sol.

    The right side of the screen, in Remix, is taken by the developer’s area. In the Compile tab, I check the Auto-Compile option, so that Remix will notify me of errors and code-analysis warnings as I write my code. The static code-analysis is controlled by the options in the tab Analysis, and I usually have all options selected.

    In the current case, Remix will report two warnings of the same kind: the methods I have written can potentially have a high-to-infinite gas cost. I will ignore that in this post.

    The above contract is very minimal. It defines a state variable store of type string, a method to set it and a method to get it. Let’s test it.

    In the Run tab, I hit Deploy and if there are no problems with the contract, a new area will appear below that button with the address where the contract is located and the functions that are available.

    Below the working area, Remix shows a detailed record of the transaction’s result. Initially, it shows only a line indicating the account that deployed the contract, the contract and method that was called, ie String.(constructor), and how much Ether was passed to the execution (initially this is shown in Wei, which is the smallest unit of Ether, corresponding to 10^-18 Ether). We can expand it by clicking over the header, revealing logs, execution and transaction costs, available gas, final result, etc.

    At this point, I just want to press the button getStore on the right, and notice how that shows beneath it the result:

    This is a well-intentioned effort, but does not work. Remix is kind enough to immediately point 4 errors and 1 warning:

    Two of these are on the same line: string newString = new string(3);

    • Warning: Variable is declared as a storage pointer. Use an explicit “storage” keyword to silence this warning.
    • TypeError: Type string memory is not implicitly convertible to expected type string storage pointer

    The other three occur in the following lines, eg newString[0] = "A"; and are all of the same type:

    • TypeError: Index access for string is not possible.

    To understand the first issue, I have to tell you about data location. Writing to the blockchain is very expensive. Every node that runs the transaction has to do the same writing, which makes the transaction more expensive and the blockchain bigger. When a node downloads a block containing this transaction, it will incur larger storage costs because of this writing. In Ethereum, every transaction has an associated cost, called gas, to incentivise programmers to be as economic as possible.

    When writing a contract, authors have a choice of what kind of data to use: memory is cheap (i.e. it costs relatively low gas, but the data are volatile and lost after a function finishes executing); storage is the most expensive (and is absolutely needed for contract state, which must persist from function call to function call); there is also a calldata location (that corresponds to the values in the stack frame of a function that is executing). This is the cheapest location to use, but it has a limited size. In particular, that means that functions may be limited in their number of arguments.

    Every data type has a default location. This is from the Solidity documentation:

    Forced data location:
    -parameters (not return) of external functions: calldata
    -state variables: storage
    Default data location:
    -parameters (also return) of functions: memory
    -all other local variables: storage

    Notice the subtlety: function parameters are by default stored in memory, except if the function is external, in which case they will be stored in the stack (ie calldata). This means that a function that is perfectly alright when public can suddenly have too many arguments when made external.

    Now, let’s come back to our code and examine the line

    string newString = new string(3);

    This is a local variable inside the function, and so by default it is in storage. The new keyword is used to specify the initial size of a memory dynamic array. Memory arrays cannot be resized. On the other hand, we can change the size of a storage dynamic array by changing its lengthproperty, but can’t use new with them.

    This is the source of our error. In this case, all we want to do with this string is create it and return it to the outside. Let the outside world decide what to do with it, and whether it is temporary only or important enough to persist on the blockchain. In this example, the storage is not important, and the string will be created in memory. To do that, we add the memory keyword in the declaration, like this: string memory newString = new string(3);

    Direct access to strings: equivalence with bytes

    Let’s see the second sort of errors now. This is simple and unavoidable: Solidity does not currently allow index access to strings. From the FAQ:

    string is basically identical to bytes only that it is assumed to hold the UTF-8 encoding of a real string. Since string stores the data in UTF-8 encoding it is quite expensive to compute the number of characters in the string (the encoding of some characters takes more than a single byte). Because of that,
    string s; s.length;
    is not yet supported and not even index access s[2]

    The alternative is to first transform the string into bytes, and then access it directly. This works because string is an array type, albeit with some restrictions.

    But there is a trap to watch out for. bytes stores raw data; string stores UTF-8 characters. The following code does not always return the number of characters in _s:

    The problem here occurs if _s contains any character that takes more than 1 byte to represent in UTF. In that case, the function returns the length of the byte representation of the input string, and will be more than the number of characters.

    This has also an impact when trying to address a particular character of the string, as we cannot predict at which location the character’s bytes will be. We have to parse the string linearly identifying any multi-byte character, or else make sure we restrict our input to characters of fixed length. If we work exclusively with ASCII strings, for example, we’ll be safe.

    Returning to our previous function, this works:

    But for example, the following code which tries to set the third character of a string to X, will fail when it receives multi-byte characters.

    This returns “AbXdef” for an input of “Abcdef”, but returns “XbÁnç!” for an input of “€bÁnç!”


    There are still many more things that can be said about this topic, but this is a long enough post already, so I’ll wrap up. The key concept regarding the type string is that this is an array of UTF-8 characters, and can be seamlessly converted to bytes. This is the only way of manipulating the string at all. But it is important to note that UTF-8 characters do not exactly match bytes. The conversion in either direction will be accurate, but there is not an immediate relation between each byte index and the corresponding string index. For most things, there may be an advantage in representing the string directly as the type bytes (avoiding conversions) and be very careful when using characters that are encoded in UTF by more than one byte.

    That’s enough for now. See you another day, with more steps in this coding adventure.

    About the Author

    Alex is a software engineer at Aventus, working on the blockchain engineering team. He has 20 years of experience working in technology, completing a PhD in Computer Science as well as a post-doctorate in Cryptography. As part of his research, Alex has published papers on Kolmogorov Complexity, Cryptography, Database Anonymization and Code Obfuscation.

    Alex also spent seven years lecturing at the University Institute of Maia, including directing the degree programmes for BSc Computer Science and Information Systems and Software.

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