Which is the appropriate word to be used in the sentence:

The system we were testing was determined to be insecure/unsecure.

The usage is in the context of security, specifically a lack thereof.

I've always said insecure, because I didn't believe unsecure was a word (although unsecured is). Even as I type this, I'm getting a spell check complaint about it. However, I was laughed at once when I called a particular device "insecure."

  • I'm not surprised they laughed at insecure device. It's pretty rare. But so is unsecure device. Both only get 2-3K Google hits when in quotes. I get orders of magnitude more hits for pretty meaningless things like blue, soft, short, sticky device. Commented Apr 6, 2011 at 2:47
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    @Fumble, I don't know why someone would laugh at "insecure device". One possibility is that they thought of the emotional meaning (not self-confident). That construction sounds normal. You're right that the exact phrase is pretty rare, but very similar constructions (insecure software, insecure computer, insecure system) are more common. Commented Apr 6, 2011 at 17:41
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    @Mathew: I personally wouldn't laugh at either adjective applied to a device. I don't really care whether I read/write insecure or unsecure, but clearly 'standard' usage is overwhelmingly insecure. What surprised me was that to the world at large, apparently, 'devices' aren't normally evaluated in terms of their security. It's mostly 'systems', 'protocols', 'communications channels', and such. Commented Apr 6, 2011 at 19:27
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    Noninunsecure devices are a threat these days :) Seriously though, as far as the word unsecure not being a word...Couldn't you say, "If you unsecure the rope, they will fall"? Commented Feb 9, 2014 at 18:58
  • Unsecured feels correct but the past tense changes the meaning ever so slightly. Even so, I think it's less incorrect to use "unsecured" than to misuse (insecure) or make up (unsecure) a word. Non-secure doesn't feel any better. I suspect there is no word and the only reasonable choice is to add a modifier like "insufficiently" or "not" to "secure".
    – Umopepisdn
    Commented Jun 5, 2017 at 21:14

10 Answers 10


I agree with Wayne Johnston, but will add some examples. Insecurity has always meant to me a lack or deficiency of security (in whatever context it is used), as opposed to a potentially secure system not being secure at this present time.

Though, I don't think it's black and white. Here are some examples of how I might use in/un-secure.

He was insecure and felt anxious when he went out with his friends.

The system is insecure and needs work before we can roll it out to production.

On the other hand:

Your bike is unsecured. Don't you have a lock for it?

The rope was unsecured. If he didn't find a hook or tree to secure it soon, the truck would fall into the ravine.

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    But you haven't given any examples of "unsecure". "Unsecured" is quite different.
    – Colin Fine
    Commented Apr 6, 2011 at 13:11
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    Unsecure isn't a word, as far people here are inclined to say. That's why I didn't use it. Commented Apr 6, 2011 at 14:36
  • Insecured doesn't sound like a word to me, so for past tense its always unsecured Commented Feb 21, 2019 at 11:05
  • It's not so much past- vs present-tense as it is that the prefixes in- and un- are modifying different parts of speech. Here, "in-" modifies the adjective "secure" (the state or quality of having security), while the "un-" in "unsecured" is modifying the past participle form of the verb "to secure" (the act of applying/enabling security). Both "secure" and "secured" behave as adjectives, and both share a common root, but have different meanings.
    – penryu
    Commented Feb 29 at 23:47

Insecure means lacking in security. Unsecured means not secured, not fastened, or not guaranteed. *Unsecure is not a word as far as I can tell.

In your example the correct usage is insecure, meaning that the security of the system was found to be lacking.

The statement, "The system we were testing was determined to be unsecured," would mean that the security was disabled, not that it was deficient.

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    The OED lists "unsecure" as obsolete (and has examples from 1656 to 1729).
    – Colin Fine
    Commented Apr 6, 2011 at 13:17
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    I would also accept "unsecured" meaning "no security at all", which is backed up by Dictionary.com's dictionaries. It would still be appropriate even if the security were not deliberately disabled. Commented Apr 6, 2011 at 17:36
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    To me it sounds like "insecure" is about judgments or expectations, implying that the thing should've been more secure than it is, or that the lack of security is a problem. "Unsecured" is more descriptive, without the implications. Commented Jul 31, 2015 at 15:50

You will find both insecure and unsecure in most dictionaries. Unsecure is generally used for assets, commodities and systems and refers entirely to safety. Insecure is used predominantly for emotional stability but also for safety, particularly in American English. Corpus searches on both words will show you this usage distribution more clearly. You can use either word, although different audiences will find it more or less strange.

  • I think this would be the most correct answer if the question wasn't asked in the context of computer security.
    – Umopepisdn
    Commented Jun 5, 2017 at 21:20
  • This should be the answer. During my undergrad years, I had a networking professor who talked about the difference. Insecure only applies to people because people can be insecure about themselves. For example - "Am I too fat??" or "Do these pants make me look fat??". However, routers, networks and other things are inanimate and can't be insecure, that'd be personifying these inanimate objects. These are unsecure.
    – rj2700
    Commented Feb 22, 2019 at 14:31

Wikipedia offers a fairly lengthy article on computer insecurity, while unsecurity returns results mostly about the United Nations Security Council. Good enough for me.

  • The article redirects to en.wikipedia.org/wiki/Computer_security now.
    – Umopepisdn
    Commented Jun 5, 2017 at 21:17
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    Nouns in "-ity" don't always take the same negative prefix as the corresponding adjective. For example, "instability" is greatly preferred over "unstability", but "unstable" is greatly preferred over "instable".
    – herisson
    Commented Nov 16, 2017 at 6:50
  • I just saw a question related to my previous comment: “Instable” or “unstable”?
    – herisson
    Commented Nov 16, 2017 at 7:26

In the context of computer security, I would actually recommend "nonsecure"; a system is secure if it is reasonably well protected against intrusion, and nonsecure if it lacks some or all reasonable measures of protection. (Note that "secure" does not guarantee that a successful intrusion is impossible, only unlikely.)

Dictionaries haven't entirely caught up to this usage yet (dictionary.com doesn't have 'nonsecure' but m-w.com does, for example) but it's fairly standard in the computer security field.


As a system never really is totally secure, you might want to use sufficient/insufficient security instead, which would circumvent the unusual unsecure/insecure phrase:

The system we were testing was determined to have sufficient security.

The system we were testing was determined to have insufficient secturity.

Sufficient security would mean that the system has reasonable security measures given it's specific situation.


As other answers have indicated, "insecure" is a much more common word than "unsecure". (The word "unsecured" has an intermediate frequency, but its meaning doesn't seem consistent with what you want.)

enter image description here

The most common nouns that occur after "unsecure" do seem relevant to your desired usage, however: the Ngram Viewer indicates that they are things like "unsecure network(s)", "unsecure line", "unsecure environment", "unsecure connection", and "unsecure channel".

The word "insecure", when used attributively before a noun, is actually often used with non-human nouns, but the top ones shown by Google are abstract like "insecure position", "insecure footing", "insecure basis", "insecure foundation(s)". So if we chose a random occurence of the word "insecure", it probably won't be related to information security. But this by no means indicates that it would be incorrect to speak of insecure devices.

In fact, because "insecure" is so much more frequent than "unsecure", the phrase "insecure network(s)" still seems to be much more common than "unsecure network"; likewise, "insecure channel" and "insecure connection" appear to be more common than "unsecure network" and "unsecure connection".

enter image description here I would say it looks like you could use either word with this meaning.


Insecure has neurotic connotations. I've always avoided applying it to things that can't suffer from that affliction unless I'm trying to be humorous.

Unsecure is more properly jargon with different specific meanings depending on context; eg. loans, physical protection (unsecured window, unsecured loan, etc). It's always unsecured rather than unsecure, but it also always has a physical and sometimes protective component.

Due to the distinct difference between the emotional and physical, I use unsecure for computing. Besides, I dislike anthropomorphizing an appliance.

IMHO, the propagation of insecure in the context of computing is a result of users whose primary source for proper English is their word processor's spell-checker. Spell-checkers typically don't support jargon.


I am not native speaker, but I found next.

The in prefix is used for situations when property is constantly exists for an object: innocent, insecure, incomplete

The un prefix is used for situation when you apply some property to an object: unsecure (remove the security); undo (make finished task incomplete); unclean (make it dirty, but it was clean before)

Thus if you are going to use unsecure:

I unsecure your network and now it is insecure

You network was unsecured by me, it is insecure now

Examples above looks reasonable to me.


I would suggest using the phrase "not secure". For example, this is what is shown in Chrome if a website is determined not to be secure.

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