Validation for a seed collision

Came across this post while researching, and it claims:

This mnemonic: weary weapon unseen like like like like like like like like like and this one: sister glide dude near muse sent like like like like like like both produce the same binary seed (which is this
in hex: 0x1003ca7a7000000000000000000000000) and they both produce
the same address list (starting with
17A2fgCpcKEbg7CbfiJwAb8sjdEzUWD2y2)

4/1000 number comes from this: (# of mnemonic permutations / # of
binary seeds) – 1 == (1626^12 / 2^128) – 1 == about 4/1000. So about 4
in 1000 mnemonics correspond to two binary seeds / two address lists.

Can someone explain/verify the reality of this? Is this true? Applicable to only 12-words mnemonic or to all? Or not valid at all?

When I went ahead and tried to use the 12-word mnemonic provided, I found out that “weary” is not even a word in BIP39 English wordlist, but words are not chosen on the basis of security but rather to reduce human error in reading and transcribing the words. Does the claim hold up? And after reading tons of information on the subject, this is the first and only source that I have seen mentioned mnemonic -> seed collision.

magento2 – Change validation dynamically on Checkout Shipping

I have a certain condition that if I have only a certain product selected then only the Email Address should be required and all other field like firstname, lastname etc will be optional and this field should be hidden. Now I managed to hide this field when that product condition was satisfied but I don’t know what to change the validation of the shipping address field. It always requires the other field like the firstname, lastname, address and etc… how can we make it optional when we arrive or loads the shipping page?

So basically I added the shouldDisplayAddress in the shipping.js

shouldDisplayAddress: function()
    {
       if (quote_items.length == 1) {
           return false;
       }

       return true;
    },

How do I make the validation for the shipping address changed? specially when I click the next button to view the Billing Address step. So I just want to dynamically change the validation.

Update:
So I found something similiar like this but I don’t know how to make the other field optional except the email address

magento2 – Remove “required field” validation in street[0] input Magento 2.3.5

I need to separate the street field into two inputs (street and number), but send them as the same field to the database.

One solution was to create these inputs, concatenate their value with Javascript and insert it into the input street (0). This works quite well, but at the time of going to the billing section I can’t move forward because it indicates that the field is empty, even when I insert a value with javascript.

how can i disable this validation?

It is not an option to use more street lines. I already use the 4 available

I know this seems strange, but because we migrate from M1 to M2 we need it in that way

php – Laravel Request validation exists e nullable ao mesmo tempo

Criei uma classe request e injeto ela no método store da controler. Meu método rules dentro da classe tem a seguinte chave:

public function rules()
{
    return (
    //...
    'campo_id' => 'sometimes|nullable|exists:tabela,pk',
    //...
    );
}

quando o valor é null e entra nessa validação, ele cai na validação exists e me retorna a mensagem correspondente. Minha intenção é deixar null mesmo. Alguma sugestão?

validation – Should comboboxes/radio groups be marked “required” in a form?

Suppose you have a web form, with some fields being optional and some being required.

One of these fields is a combobox or radio button group, for which a valid default option is pre-selected and it is not possible to “un-set” this field.

In other words, this field is always valid for submission, but potentially not correct, and I can’t have users “glossing over” that field as many will with all of the “optional” fields.

Should this field be marked “required”?

Note: I would prefer to keep the default pre-selected option, because this value is the correct value for more than half of the use cases by volume.

automata – validation of a pumping lemma proof for regular languages

i have the following regular expression:

image of the regular expression

of course i could think of a world like w=a^(m+2)b^(m+2)c^(2m+3) and continue with the proof BUT
i was just wondering, because L is made up of a union of two expressions, is it valid to split L into
L1=a^(i)b^(j)c^(2j-1)| i<=j & i,j>0
L2=a^(i)b^(j)c^(2j-1)| i>=2j-1 & i,j>0

show for each L1 and L2 that the pummping lemma does not work on them (so for l1 i just show that for lets say each k i is not smaller or equal to j, and for l2 i show that i is not always bigger or equal to 2j-1 for each k)

by that i show that l1 and l2 are not regular which means that the union of the two will also be not regular.. is this corrent?

thank you.

validation – Requirement Verification – Software Engineering Stack Exchange

According to what I understand, Requirement validation involves going over the SRS to ensure the requirements is correct with respect to user needs.

1- Could you help clarify verifiable requirement (checked during validation)?
2- What is the difference between “requirement verification” and “requirement validation”?

An example to clarify the concepts would be great. Thanks

Google Sheet Column Tick box validation

Complete newbie here, sorry if this sounds silly.

I have 3 columns and 60 rows of tick boxes, I have the tick boxes adding up at the bottom of the sheet.

Question is I do not want a user to tick more than the available ticks per column each column has a maximum amount of tick boxes available.

For example column, A max ticks allowed is 12, B max ticks allowed 7 and C Max 25.

performance – Entity delete validation in a microservice environment

In a microservice environment there are two services: Service A and Service B.

Service A manages an entity called x which has one to many relationship with service B’s entity called y

When a network request hits to Service A to delete a specific x, Service A makes an internal network request to service B to validate whether specific x being used with any y item.

In a microservice environment, is there a better and more efficient way to handle this kind of request and validation among two services?

Also these options already came to table, however not optimal.

  1. Managing a cache on Service A about y isn’t viable.
  2. Managing a key/property on each x about whether it’s being used or not, was
    also considered. However there’s a development overhead of migrating
    all the old data with new property.
  3. Let the front-end (webapp) directly calls Service B’s validation before hitting to delete. However there’s a possibility to have a false positive with the timing.

performance – Entity delete validation in a microservice envirenment

In a micro service environment there are two services. Service A and service B.

Service A manages an entity called x which has one to many relationship with service B’s entity called y

When a network request hits to Service A to delete a specific x, Service A makes an internal network request to service B to validate whether specific x being used with any y item.

In a micro service environment, is there a better and more efficient way to handle this kind of request and validation among two services?

Also these options already came to table, however not optimal.

  1. Managing a cache on Service A about y isn’t viable.
  2. Managing a key/property on each x about whether it’s being used or not, was
    also considered. However there’s a development overhead of migrating
    all the old data with new property.
  3. Let the front-end (webapp) directly calls Service B’s validation before hitting to delete. However there’s a possibility to have a false positive with the timing.