The uniqueness of participants is proven by the fact that they must solve and provide the answers for flip-puzzles synchronously. A single person is not able to validate herself multiple times because of the very limited timeframe for the submission of the answers.

El estado de validación de un participante no es para siempre. Caduca cuando comienza la próxima época. Los participantes deben prolongar su estado de validación para cada nueva época.

Técnicamente, una cuenta se puede vender y comprar. Sin embargo, el protocolo Idena introduce incentivos económicos para evitar que los participantes lo hagan. Una persona que vende su cuenta puede simplemente matar la identidad criptográfica después para desbloquear sus monedas congeladas (las monedas congeladas se acumulan para cada cuenta como parte de UBI y no se pueden gastar mientras la cuenta sea válida).

Para vender una cuenta, el vendedor proporciona una copia de la clave privada de la cuenta. El comprador no puede estar seguro de que otra copia de la clave privada no se quede con el vendedor. Por lo tanto, la clave privada permite al vendedor eliminar la criptoidentidad en cualquier momento, y el comprador no tendría una razón económica para comprar una cuenta de Idena.

Para usar Idena solo para enviar monedas, solo necesita descargar la aplicación. Para crear una identidad criptográfica y comenzar a extraer monedas, debe recibir un código de invitación de un participante validado de la red y usar el código para solicitar la validación.

New invitations can only be sent out by validated members. Join the official Idena Telegram chat and follow instructions in the pinned message to get an invitation from validated members or the Idena team. Invitations should be granted for free. Do not pay money for an invitation because the person who sells an invitation can terminate the invitation and issue a new one.

Please notice that validated members have limited number of invites (1 or 2 invites). The person who invites you gets invitation rewards for 3 subsequent validations passed by you. If you are not going to participate in the upcoming validation, please notify the person who invited you so they could have a chance to find another invitee and get an invitation reward.

You also get a part of invitation rewards based on the inviter's stake. The higher the inviter's stake, the more reward you get if you pass the validation. The reward are sent to your stake. If your inviter is penalized for a reported flip, the invitation rewards are not paid neither to the inviter nor to you. Please see details here.

Be aware that person who invites you can terminate your Candidate account until you get Newbie status.

• Download and install the Idena Node and Idena Client executable files or build them from source.
• Subscribe to the Idena Announcements Telegram channel to follow updates.
• Join the official Idena Telegram chat and follow instructions in the pinned message to get an invitation code.
• Asegúrese de que su nodo esté sincronizado y active el código de invitación. Verifique el estado de su identidad; debería ser "Candidato."
• Check the next validation time: ... Your node must be synchronized before the session starts.
• Learn how to solve flips: read the article in our blog and test yourself.
• Resuelve los flips durante el tiempo de validación. Sea ágil. Los primeros 6 lanzamientos deben enviarse en menos de 2 minutos.
• Una vez que su cuenta esté validada, mantenga su nodo en funcionamiento para minar monedas.
• Aprenda a crear flips. No olvide crear tres flips antes de la próxima validación por adelantado. Programe su próxima validación.

El ritmo de crecimiento de la red está restringido para minimizar la probabilidad de un ataque Sybil.

The Idena protocol introduces incentives to prevent participants from buying and selling invitations. The person who sells an invitation can kill the invited participant and get the staked/locked coins during the next several epochs before their status is "Newbie". The seller can double-spend the invitation by selling it multiple times. Invitations should be granted for free to trusted people only (relatives, friends, and so on).

El número objetivo de invitaciones en la red se calcula como el 50% del tamaño de la red después de cada validación (las invitaciones de la fundación Idena son adicionales).

Invitations are distributed as follows:

• Identities with the Human status get one invitation starting with the highest Total score.
• If there are non-distributed invitations left, identities with the Human or Verified status get one invitation starting from the highest total score.
• After the distribution, the minimal Total score of those entitled to receive invitations is known.
• All identities with this minimal Total score receive invitations. If needed, additional invitations are issued by the Idena protocol to cover the demand.

The core Idena team is granted to issue a limited number of invitations per epoch to support the network growth. The number of available invitations for the foundation address is limited to min(500, NetworkSize*0.1))

Cada cuenta en Idena tiene dos billeteras: la billetera Idena y la stake. La stake es como su cuenta de pensión: el 20% de todas sus recompensas de Idena (minería, recompensas de validación, recompensas de inversión, recompensas de invitaciones válidas, etc.) se acumulan en la stake, mientras que el 80% restante va directamente a su billetera de Idena.

La stake no se puede gastar mientras su cuenta sea válida. Recibe estas monedas en su billetera Idena solo cuando cancela voluntariamente su cuenta Idena, es decir, cuando "mata" su identidad criptográfica.

Cuando su cuenta es eliminada por el protocolo de red, pierde su stake.

Idena no utiliza el stake con fines de gobernanza.

Discriminación de identidades con el estado de novato

Solo el 20% de las monedas ganadas se extrae a la billetera principal para Novatos. El 80% restante se extrae de la stake: en total, el 60% de las monedas ganadas se bloquea temporalmente en la stake hasta que un novato se convierte en verificado.

El 60% de las monedas ganadas se enviarán de vuelta a la billetera principal una vez que un novato se haya verificado.

Los novatos no pueden rescindir sus identidades para retirar el stake.

Newbies cannot participate in the governance of the network. While adresses with this status can get rewards for mining and participating in oracle votes, their votes are not counted and do not make a difference in the final outcome of a voting: they cannot influence a hard fork voting or an oracle voting.

La fecha de la sesión de validación la calcula la red y se muestra en la aplicación Idena. La hora siempre es fija: 15:00 UTC.

Cuanto más grande es la red, con menor frecuencia ocurren las sesiones de validación. Read more.

La hora de validación de las 15:00 UTC cubre la mayoría de los países cuando la mayoría de las personas están despiertas. Estos son los horarios locales de algunas de las ciudades del mundo (a partir del 1 de junio de 2019):

• San Francisco, USA 8:00
• New York, USA 11:00
• London, UK 15:00
• Berlin, Germany 16:00
• Moscow, Russia 18:00
• Delhi, India 20:30
• Beijing, China 23:00
• Tokio, Japan 24:00

La sesión de validación corta tiene un período de tiempo muy limitado, menos de dos minutos, y consta de seis flips, cada uno de los cuales es recibido solo por 1 a 4 participantes en la red (dependiendo del tamaño de la red). La tarea de esta sesión es realizar una prueba de Turing: distinguir a los humanos de la IA.

La larga sesión de calificación de flip dura 30 minutos y consta de 25-30 flip, cada uno de los cuales es recibido por un mayor número de participantes de la red (dependiendo del tamaño de la red). Esta sesión permite a la red lograr un consenso sobre la calidad del flip y la respuesta correcta a un flip.

Para ser validado, debe cumplir estos tres requisitos durante cada sesión de validación:

• La puntuación de su sesión de validación corta actual debe ser del 60% o más.
• Su puntaje total para las últimas 10 validaciones breves (incluida la sesión de validación actual y todas las anteriores) debe ser del 75% o más.
• La puntuación de su sesión larga actual debe ser del 75% o más.



Además, debes resolver flips de forma correcta y rápida. Los primeros 6 flips deben resolverse en menos de 2 minutos.

El estado de validación de un participante no es para siempre. Caduca cuando comienza la próxima época. Los participantes deben prolongar su estado de validación para cada nueva época. Una persona validada puede perderse dos sesiones de validación seguidas sin perder su criptoidentidad. Pero esta persona no puede minar monedas durante las épocas en las que se han perdido las validaciones.

El tiempo de validación debe sincronizarse para que personas de todo el mundo verifiquen la singularidad de los participantes de la red. De lo contrario, sería posible verificar una cuenta diferente en cada una de las diversas ceremonias de validación.

Los novatos y las cuentas verificadas deben enviar flips antes de la próxima ceremonia de validación. No enviar volteretas equivale a perder una validación.

Los candidatos, las cuentas suspendidas y los zombis no envían flips para la ceremonia de validación.

Si su criptoidentidad es eliminada por la red, pierde su participación: 20% de todas sus recompensas (minería, recompensas de validación, recompensas de inversión, recompensas de invitación válidas, etc.), que no se pueden gastar mientras su cuenta de Idena sea válida y que solo se puede recibir cuando cancela voluntariamente su cuenta.

El 80% restante de todas sus ganancias de Idena van directamente a su billetera Idena. Conserva esas monedas incluso si su criptoidentidad muere (por usted o por el protocolo de red).

It is possible in the one of following cases:

• If one of your flips is reported by the majority of qualification committee (please see What if one of my flips is reported)



or

• If all of your flips have status No consensus which means that the network could not reached consensus about the right answer for these flips.

Please notice that flips are the key element of Idena network security. That is why the protocol imposes severe penalties on users that create flips in breach of the rules.

As Idena is a decentralized and distributed network it uses a gossip peer-to-peer protocol to ensure data disseminated to the network.

To consider your answers valid they should reach more than 50% of validated nodes no later than 15:02 UTC.

Also, the keys of your flips (for previously validated users) should spread across the network no later than 30 secs from the beginning of validation.

If your node lost connection while submitting the answers/keys and connection was restored after the above time, the validation attempt will be considered as failed with the Late submission reason.

We recommend you to keep your desktop node synchronized at least 30 mins before validation, upgrade your hardware if possible or use Idena web app (app.idena.io) with a connection to one of shared nodes for validation.

Los participantes validados crean flips para poder participar en la próxima sesión de validación.

Por ahora, no pueden. Pero Idena está diseñado como un proyecto de código abierto, y esperamos que haya equipos con experiencia específica en esta área que estén motivados para desarrollar medios para que las personas con discapacidad se validen en la red, como audio flips, por ejemplo.

Se envía un flip sin la respuesta correcta. La red llega a un consenso sobre la respuesta correcta después de la sesión de validación.

Si no se alcanza el consenso, se descalifica el flip. Las respuestas de los lanzamientos descalificados no se cuentan. Los autores de lanzamientos descalificados no reciben recompensa por realizarlos.

Flip tiene un fuerte consenso si no menos del 75% de los participantes están de acuerdo con la respuesta. Los participantes que dieron la respuesta correcta obtienen 1 punto, de lo contrario 0.

Flip tiene un consenso débil si al menos el 66% de los participantes están de acuerdo con la respuesta. Los participantes que dieron una respuesta correcta obtienen 1 punto, de lo contrario 0,5.

La red llega a un consenso sobre la respuesta correcta después de la sesión de validación. Si no se alcanza el consenso, se descalifica el flip. Las respuestas para tales giros descalificados no se cuentan.

A medida que la red crece, la cantidad de personas que resuelven el mismo flip disminuye: en una red de 10,000 usuarios, solo dos participantes diferentes tendrán el mismo flip para resolver. Cuando la red alcance los 30.000 usuarios, aparecerá un solo cambio en una sesión de validación de un solo participante.

Los flips se almacenan como datos cifrados en la red antes de la validación y luego se distribuyen algorítmicamente.

Los flips están encriptados de acuerdo con el siguiente protocolo:

1. Every flip has a public and a hidden part:
   - the public part is available for everyone after the validation (2 images)
   - the hidden part is available only for the participants who solve the flip
2. An author generates 2 keys for flip encryption:
   - FlipPublicSecret for the encryption of the public part of the flip
   - FlipHiddenSecret for the encryption of the hidden part of the flip
3. Todos los flips creados por el autor se cifran con estas 2 claves y se transmiten al IPFS
4. Flip lottery
   - The author calculates the list of candidates who must solve the flips in order to send them FlipHiddenSecret
   - FlipRecipients[N] array is produced: FlipHiddenSecret is encrypted N times with candidates' public keys (N is the number of participants who must solve the flip)
   - FlipRecipients[N] array is encrypted with FlipPublicSecret and broadcasted to the IPFS
   - Candidates download arrays FlipRecipients[N] corresponding to the flips they have to solve
5. Once the validation ceremony starts at 15:00 UTC, all the authors broadcast their FlipPublicSecret.
   - Candidates decrypt arrays FlipRecipients[N] corresponding to the flips they need and extract the FlipHiddenSecret using their private key.
   - Other participants can decrypt only public parts of the flips using shared FlipPublicSecret.

Los flips pertenecen a la clase de problemas difíciles de la IA. No existe un patrón único para los flips, ya que son creados por humanos de acuerdo con palabras clave seleccionadas al azar.

Los flips no pertenecen a la clase de problemas de "reconocimiento", que se resuelven fácilmente mediante redes neuronales. Resolver un cambio exige comprender el significado de una historia, utilizando un razonamiento de sentido común.

El ejemplo del Winograd Schema Challenge muestra que la introducción de una base de datos más grande no conduce a mejores resultados con las tareas difíciles de la IA.

In addition, adversarial noise can be added to flip images to make a neural network result in incorrect outputs.

Por lo tanto, los instrumentos de IA actuales o incluso una gran base de datos de flips no lograrán los resultados que se pueden comparar con los demostrados por los humanos.

Debe reportar el flip cuando vea uno de los siguientes:

• Una de las palabras clave no es relevante para el flip
• Necesitas leer el texto en el reverso para resolverlo
• Ves contenido inapropiado
• Ve números o letras u otras etiquetas en la parte superior de las imágenes que indican su orden

Cada informe exitoso de un flip es recompensado: la recompensa por el flip informado que no se paga al creador del flip se distribuye entre los miembros del comité que informaron el flip.

El número de flips que se pueden informar está limitado a 1/3. Por lo tanto, los participantes están motivados para elegir qué flip informar primero basándose en criterios objetivos (por ejemplo, la relevancia de ambas palabras clave).

Flips are the key element of Idena network security. The protocol imposes severe penalties on users that create flips in breach of the rules. If one of the flips is reported during the validation, the user that created this flip will not get any rewards for the validation. A flip cannot get status Reported by accident. This status is given if more than 50% of qualification committee have reported this flip during the long session. Every member of qualification committee can report only 1/3 of flips that are shown to them.

Para crear un flip, usa dos palabras clave seleccionadas al azar por el protocolo como sugerencias asociativas para pensar una historia dentro de la plantilla general de "Antes - Algo sucede - Después". Subes cuatro imágenes desde tu dispositivo o desde Internet para contar la historia. Luego, crea una alternativa, una secuencia sin sentido de las imágenes que ha elegido barajando, y envía el par de secuencias a la red.

Please follow the rules when creating flips:

• both keywords should be clearly visible in the images
• flips should not contain any numbers or letters or other labels on top of the images indicating their order
• flips should not contain any sequence of enumerated objects
• flips should not content any text that is necessary to understand to solve this flip
• flips should not contain any adult content (18+, NSFW)
• flips should not contain several unrelated stories
• flips should not include waking up template
• there should not be thumbs up/down image at the end
• do not insert images of both keywords into a page/screen/painting

If you don’t follow these rules when creating a flip, it can be reported at the qualification session. Please keep in mind that in this case you will not be paid for validation (see What if one of my flips is reported).

Estas dos palabras clave seleccionadas al azar de un gran diccionario son una especie de sugerencia asociativa para estimular su creatividad. Debe utilizarlos por dos razones. En primer lugar, hacerlo ayuda a garantizar la no repetibilidad y la imprevisibilidad de los tipos de flips lo que hace que los flips sean realmente resistentes a la IA. En segundo lugar, permite que el protocolo Idena detecte y castigue el abuso del protocolo, como enviar una serie de imágenes aleatorias en lugar de un flip o el mismo flip repetidamente.

Network participants must create flips relevant to the suggested keywords. If you are not sure of the meanings of the word, or if you cannot think of a story with the suggested words, click the Change my words button, and a new pair of words will appear. You are given 9 pairs of words to create three flips each epoch.

La relevancia del cambio a las palabras clave se prueba durante la larga sesión de calificación. Los participantes que crean flips que son irrelevantes para las palabras clave son penalizados por el protocolo. Las identidades se eliminarán por ignorar repetidamente las palabras clave al crear flips.

Los flips son creados por identidades validadas.

La red llega a un consenso sobre la respuesta correcta después de la sesión de validación. Si no se alcanza el consenso, se descalifica el flip. Las respuestas de los flips descalificados no se cuentan y los autores de estos flip no son recompensados.

No puede guardar borradores para la próxima época, porque las palabras clave utilizadas para la creación de copias se generan para la época actual. Todos los borradores se grabarán después de la sesión de validación y tendrá que crear nuevos flips.

Los usuarios que creen flips sin sentido o spam o flips con contenido inapropiado o irrelevantes para las palabras clave deben ser castigados.

Flips are distributed randomly. Participants are not allowed to solve flips created by themselves.

You can delegate your mining status to another address which in this case will act as a pool.

For example, if several members of your family have Idena nodes, you can benefit from delegation to one pool. Only this pool node has to be online to mine coins for delegated nodes. Pool rewards for block mining will be equal to those of a single identity.

Mining and validation rewards will go to the pool address. Your address will get only the part of rewards that goes to your stake.

Please keep in mind that your identity could be terminated by the pool owner and you can lose your stake. That is why we strongly recommend to use delegation only if you trust the pool owner.

You can disable delegation in the next epoch only.

No keys are transferred from the delegating node to the pool. The fact of the delegation is stored only on the blockchain.

However, the pool owner can terminate your identity and take your stake.

Any validated user can delegate their mining status to a not validated address which will become a pool.

Yes, you need to stay validated so that the pool can keep mining coins for you.

Yes, you can vote in any Oracle voting and get rewards in accordance with the specific oracle voting. These rewards will go to the pool address.

However, to determine the results of the Oracle voting only the last vote sent from the pool is counted.

In addition to the rewards for flips, reporting "bad" flips, invites, the Idena protocol offers rewards for staking. Unlike traditional linear staking, where large coin holders benefit the most, Identity Staking allows small-scale stakeholders to earn a higher APY than larger stakeholders. The Identity staking rewards are paid only to validated identities in proportion to their stake raised to the power of 0.9

Only validated identities can earn Identity staking rewards. There are two types of rewards you can earn.

1. Validation rewards. You can get Identity staking rewards for the successful validation once per epoch in addition to the basic rewards for invites, flips and reporting. The bigger your stake the more you get for validation.
2. Mining rewards. Mining rewards are paid out in real time as long as you keep your Idena node up and running while your mining status is activated. You can run the Idena node on your laptop in the background. It does not require a mining rig and does not consume much electricity. By running your own node you contribute to the network security and decentralization.

You can calculate your estimated Identity staking rewards here:
https://www.idena.io/staking

Please be careful as you can lose your stake for missing or failing validation depending on your identity status.

If you want to withdraw your stake you need to terminate your identity. You can not withdraw your stake until you get Verified status. We recommend you to start staking your coins only when you have Human or at least Verified status. However you can take a risk and start earning staking rewards even with Candidate status.

• Candidate. You can stake the coins and get staking rewards for your 1st validation. However, before your 1st validation the user who gave you the invitation code can terminate your identity and burn your stake. If you still want to stake, please do not miss or fail your validation. Otherwise, the stake will be burnt. You won’t be able to withdraw your stake until you get validated at least 3 times in a row and get the Verified status.
• Newbie. You can stake your coins and earn both rewards for validation and rewards for running your own Idena node. 80% of your rewards will be locked in your stake until you get Verified status. 60% of these rewards will be sent back to your wallet once you reach Verified status.
  Please keep in mind that while you have a Newbie status you can not terminate your identity and withdraw your stake. You need to reach Verified status to be able to do it.
• Verified. You can not fail the next validation, otherwise your coins will be burnt. However, you can miss validation and get Suspended status. With Verified status you can terminate your identity to withdraw your stake.
• Human. Human status allows you to stake your coins safely. You will not lose your stake even if you fail or miss the next validation. However, your status will be switched to Suspended.
• Suspended. You can not earn mining rewards with Suspended status. However, if you join the next validation you can earn the staking rewards for validation and restore your Human status. If you fail your next validation your stake may be burnt depending on your age (see table below). If you miss your next validation your stake will remain and you will get Zombie status.
• Zombie. If you miss the next validation the stake will be burnt. However, if you fail your next validation then only a part of your stake can be burnt depending on your age. Remaining part will be sent to your main wallet.

Total supply is not limited.

Total minting is capped at 51,840 coins per day. Half of the cap (50%) is mined while producing the blocks. The rest of the coins are minted during validation sessions.

Block reward: 6 iDNA
Maximum number of blocks per day: 4,320
Mining cap per day: 25,920 iDNA (50%)
Accumulating fund per day: 25,920 iDNA (50%)
Total cap: 51,840 iDNA

There are the following cases for supply utilization:

• 20% of minted coins are frozen in stakes
• Stakes of non-validated identities are burnt
• Mining penalties are burnt
• 90% of transaction fees are burnt
• 1% of the minted coins are frozen in the zero wallet
• 100% of ad payments will be burnt: read more
• The bigger the network the more coinholders will just hold newly minted coins without spending them

Account gets a penalty equal to 8 hours of burning mining.

An Idena validator receives the mining penalty if their node is inactive for more than 1.5 hours. The miner status for the penalized account is deactivated automatically. Account gets a penalty equal to 8 hours of burning.

To continue mining, the mining status has to be activated manually. As the validator’s node returns to mining, the penalty time decreases, and the mined coins are burnt.

Every node tracks activity of other nodes when new blocks are produced. There are two subsequent blocks that have to be mined to penalize an offline node:

1. Penalty proposal block (OfflinePropose bit is activated)
Nodes are voting for a penalty proposal by a special bit in their vote messages: TurnOffline.

2. Penalty execution block (OfflineCommit bit is activated)
The block is created if consensus for the penalty proposal mined in the previous block is reached.

The transaction fee is calculated automatically by protocol. The fee goes up or down based on how full the previous block was, targeting an average block utilization of 50%. When the previous block is more than 50% full, the transaction fee goes up proportionally. When it is below 50% usage, fees go down. A user can specify the maximum fee limit for the transaction.

transactionFee = currFeeRate x transactionSize

currFeeRate = max(
     1e-16,
     0.1/networkSize,
     prevFeeRate*(1+0.25*(prevBlockSize/300Kb-0.5))
    )

Validation ceremony transactions are not charged. However, they affect the fee rate because of the block consumtion.

90% of paid fees are burnt. The rest 10% are paid to the block proposer.

There is a fixed cap for minting Idena coins equal to 51,840 iDNA per day:

• Block mining cap: 50%
• Staking reward fund: 9%
• Candidate reward fund: 1%
• Flip reward fund: 7.5%
• Extra flip reward fund: 10%
• Invitation reward fund: 9%
• Report reward fund: 7.5%
• Idena foundation payouts: 5%
• Zero wallet fund: 1%

The validation session fund is capped at 25,920 iDNA per day. It accumulates daily (according to the number of blocks issued) and gets distributed at the end of the validation session. Please see the validation rewards distribution here.

No rewards are paid to those participants who fall into one of the following groups:

1. Participants who have at least one reported flip
2. Participants who have no qualified flips
3. Participants who provided invalid data instead of flip images

Idena formalizes people on the blockchain and there might be use cases that we can not anticipate yet.

Idena participants voluntarily agree to consume ads published by a valid address which burns coins. Multiple advertisers compete for attention of a certain group of users by burning coins. This is an auction: Whoever burns more coins has the right to show their ad. Burnt coins are removed from the total supply. Newly mined coins are equally distributed among the network participants and then can be sold to advertisers who will have shortage of coins.

Fig: Closed tokenomics fuels the demand for the Idena coin

1% of all issued coins is accumulated at the zero wallet address. We believe that a governance for the zero wallet fund allocation will be established in future. It can be used for the external projects funding, covering someones losses or for some other purporses the network agrees on.

There is no private key for the zero address. The network must reach consensus in order to spend it.

Create an account on one of the exchanges where iDNA is traded. Trade iDNA and withdraw it to your wallet. If you want to hold iDNA long-term, we do not recommend storing your coins on the exchange for safety reasons.

You can use the Idena Web App or one of the Idena wallets created by the community to store your iDNA. Choose a wallet you want to use, generate your address and use it to transfer your Idena coins. In general, storing coins in a private wallet is safer than keeping them on an exchange.

You can buy wrapped iDNA on a decentralized exchange using your metamask wallet. Open pancakeswap, click Trade and connect your wallet. Read more about using your metamask wallet with BSC blockchain to trade iDNA.

If you have traded wrapped iDNA on BSC blockchain and want to store them on the Idena blockchain, you can swap your iDNA using the Idena Bridge.

This is a general safety assumption applicable to any permissionless blockchain and it is not possible to overcome it: More than 2/3 of honest participants are needed to guarantee safety.

Let's look at Bitcoin proof-of-work. Consider selfish mining when the biggest miners are getting bigger. As a result, small miners do not invest in Bitcoin mining since it contributes to their losses. As a matter of fact, there is highly concentrated mining in Bitcoin that cannot ever be reverted. There are thirteen controlling pools in Bitcoin. There are three pools controlling more than 50 percent of the Bitcoin network.

The captcha test starts synchronously at the same time worldwide. Answers must be submitted within an aggressive timeframe. An attack requires extensive coordination of a high number of unique workers.

In addition, since the validation timeframe is relatively small (1–2 minutes), the workers might be interested in validating their own identities instead of selling their time during the validation time.

Attack: An adversary offers a flip service that creates high quality flips using the set of words you specify. Participants who don't want to spend time creating flips can outsource this job to the service. If the service has enough users it can auto-solve a significant number of flips.

The threat can be mitigated by introducing a punishment mechanism: An account can be killed for submitting a compromised flip for validation. A flip is considered compromised if it has been seen by other people before the validation time. A hash of the proof published on the blockchain prior the validation can be considered as evidence. The person who provides the evidence earns percentage of the stake of the terminated account.

Effectively, once you decide to submit at least one flip provided by a flip service, you take a risk that your account may be terminated by this service in future.

A flip service can not prove that it does not publish evidence of compromised flips. It will hardly be profitable to build such a service on reputation since there is a strong incentive to kill accounts later on when more accounts are compromised and the total stake of those accounts is big enough.

Attack: Users in an attacking pool share the flips they submitted to the network with other users in the pool before the validation. This allows the pool to validate Sybil accounts.

Assume the total network size is 1000. An adversary has a pool of 100 people colluded. the adversary knows the answers for 10% of flips in advance. This means the adversary can validate 1% of Sybils by colluding (10 accounts).

On the next round the adversary knows 11% of the flips so they can validate 1.1% of Sybils (11 accounts). The adversary can only grow extensively: More and more real people have to collude.

Compared to PoS, getting 10% of the actual humans in the network to collude is harder than merely having capital equivalent to 10% of the network’s market cap.

Attack: AI can learn to solve flips by having a huge dataset of flips produced by a big network: 1 million network of people will generate millions of flips per epoch which is enough for machine learning.

The threat is mitigated by flips encryption. Each flip is available only for those participants who solve it during the validation session. There are around 10-15 persons who see it. The flips that have been used for validation are encrypted: Only 2 out of 4 images of a flip are publicly available to make it impossible to easily collect huge datasets.