System Identity Implementation

Every CIYAM node requires its own “identity” in order to differentiate it from all other nodes and which also will allow its backup data to be restored (assuming that at least one “backup peer” exists). When it is first started a list of twelve randomly chosen words (from a small dictionary of 2048 words) appears in the browser interface (along with fields for a master password that is used to encrypt these words prior to being written to the node’s primary storage device).

Keeping Your Identity Secure

In order to be able to later restore backup data the twelve words (also known as “mnemonics”) need to kept in a manner that is secure from theft (including being secure from hacking) and accidental loss. When starting a node for the first time it would be recommended that no internet connection be provided until after you first have made a copy of the twelve words (using an analog method such as pen and paper) and have also entered the master password (which should be typed in twice manually to confirm that it is correct).

After creating it would be suggested to then reboot the node (or restart the CIYAM service) and then from the browser when prompted to “Enter unlock key or system identity password” instead type 7 asterisks (*******) to force the “Reset Master Password” dialog to appear. This permits a new master password to be entered (just in case it was forgotton) and requires the original 12 words (and any extra characters) to be provided. The same master password can now be provided (i.e. it does not need to be changed) but by performing this step it will confirm that the system identity can be restored in the future (i.e. that the words were correctly recorded).

The master password is hardened (with over 1.1M hash operations) in order to ensure that any attempt to crack it by brute force would take a very long time, however, it would still be recommended to use a password which includes special characters, digits and both lower and upper case letters and which is at least 10 characters in length.

Administration PIN

Immediately after completing the Confirm Identity (or Reset Password) form the “Administration PIN” form will appear which displays a 5 digit PIN. This should be recorded (in writing preferrably) for use as the Username when wanting to “sign in” as the “admin” user (i.e. providing the Username “admin” will always fail). Also it should be noted that the Password for this “admin” user is the same as the master password and that resetting the master password will always change the PIN (even if the actual master password is unchanged).

The reason for using a 5 digit PIN is because the browser UI hashes the combined Username and Password values around 12K times (rather than the 1.1M rounds that are used to encrypt the mnemonics). The reason for this is to not burden the browser (especially when used on a phone) with a potentially large time and power consuming operation. Without further entropy this would make cracking the master password (which is being also used for the “admin” account password) much easier so the additional 5 numbers (which are randomly picked) effectively makes the “admin” password hash just as safe from a brute-force attack without needing any additional rounds.

Calculating Password Strength

A typical high-end Bitcoin mining device can perform 200 TH/s and although the way that CIYAM hash operations are performed is not the same (meaning a specific ASIC device would need to be manufactured for this purpose) this can be a useful way to perform some “back of the envelope” calculations to measure just how much a brute force attack on a password would cost in terms of hashing time. In order to make the calulations a bit easier the relevant numbers will be rounded. Although over 1.1M hashes are performed per password attempt the number will be rounded down to 1M and although there are 95 different characters that could be typed with a standard keyboard this will be rounded up to 100.

200,000,000,000,000 (200 TH/s - Bitcoin mining device) 1,000,000 (number of hashes required for a password) 100 (number of possible character values) 10 (recommended minimum password characters)

If a single character password can have 100 possible values then a brute force attack would try each possible value until the correct password is found (which on average would take 50% of all the possible combinations). So a password of 2 characters would require on average (100x100)/2 attempts and likewise a password of length 3 would require on average (100x100x100)/2. So with every increase in length the total number of combinations is multiplied by the number of possible characters. So a password with 10 characters would 100x100x100…x100 or a 1 followed by 20 zeroes (100,000,000,000,000,000,000). Next it needs to be taken into account the number of hashes per password attempt (1,000,000) so we add another 6 zeros (now 26 zeroes). Using a 200 TH/s device means that we remove 14 zeroes and then divide by 2 to leave a 5 followed by 11 zeroes. Dividing by two again to get the average number of seconds to brute force the password would be 250,000,000,000. In minutes this is over 4 billion which in years is more 7,500!

If the password is not strong then of course it could be brute forced in a small fraction of this time so the use of a strong password is highly recommended (and should be considered essential if other people could ever have physical access to the node device).

Restoring an Existing Identity

If wishing to restore an already existing CIYAM system using a new node then the twelve words which initially appear should be replaced with those that had been written down previously (the master password that had been used before is not relevant when restoring so a new one can be provided **).

Enhancing Your Identity Security

It should be noted that the dictionary being used is that defined by BIP39 (being the standard used in crypto wallets). Although it might be a convenience to use the same words for both your crypto wallet and CIYAM node THIS SHOULD NEVER BE DONE as it could lead to the loss of all your crypto assets.

As the dictionary is 2048 words each single word is 11 bits (1024 being 10 bits so 2048 being one extra bit). This means that twelve words is 132 bits, however, to minimise human error the last 4 bits are being used for a “checksum” (to detect input mistakes) so there are only 128 bits of “entropy” (or randomness) present.

This is a lot of entropy but if wanting to be “future proof” one might want to extend this even further. This is why some crypto wallets have 18 or 24 words as an option (rather than just 12). The CIYAM node permits you to add extra characters after the twelve words (with a space separating the last of the twelve words from the first of the extra characters) which are used to “harden” the 128 bits of entropy (with over one million hash operations being performed after combining the extra characters with the seed value of the twelve mnemonics).

It should be noted that any extra characters provided are not BIP39 mnemonics and so if entered incorrectly will simply result in the wrong identity (with no error being issued) so be very careful when recording these along with the other twelve words for safe keeping.

Identity and Mnemonic Passphrase Examples

These are some sample blockchains that have been created purely for testing purposes:

Identity: 6d0469dd5 Mnemonics: carpet purpose exit uncover change ahead soft solve cram long jump ripple

Identity: 6f2680b40 Mnemonics: detect jazz kick ghost novel rifle scout mirror stairs craft outdoor crisp

Identity: 6b24210e8 Mnemonics: taxi act describe attitude focus ugly govern outer note isolate endless act

It should be noted that an identity will always be exactly 9 characters in length and because every character has one of sixteen possible values this length is enough to provide tens of billions of different identities.

Using additonal characters in order to create a more “future proof” identity:

Identity: 59a23c2bb Mnemonics: detect jazz kick ghost novel rifle scout mirror stairs craft outdoor crisp #!@A11E4sy

System Unlock Keys

Although the master password can be used to unlock a CIYAM node (after a reboot or service restart) it is not recommended to enter the master password from another device (and in particular from an outside network). For this reason when logged in as “admin” from the System Information view a “Generate Unlock Key” action appears in order to create a “one-off” password for unlocking the system.

When an unlock key is created 11 random “alphanumeric” characters are hardened (by 5+ million hash rounds) to then be used to encrypt a hash of the system identity which is stored as a file (the name being obtained from a substring of the hex characters from the hardened password’s hash).

Once the unlock key has been used the file will be deleted (thus each unlock key can only be used once). Many unlock keys can be created so it is recommended to always have a few (and to create replacement keys prior to using up all those that had been previously created).

To improve readability the 11 random alphanumeric characters are encoded to 15 base64 URL characters which in turn are split into sets of 5 (with two space separators). To make things easier when using the browser UI/UX a button will copy the unlock key characters to the clipboard (although it is recommended to later write them down on paper).

As the unlock key encrypts the system identity “hash” (and not the original passphrase) they will never allow the original passphrase to be discovered and therefore are the recommended way for unlocking a node (usage of the master password should be limited to only when physical access to the node is possible).

** If after restoring a CIYAM system an unlock key is used (rather than the new master password) then “admin” will not have its password changed (so normally this situation should be avoided by using the master password to perform the initial “unlock” for a restored CIYAM system).