Secure Hash Algorithm is a family of cryptographic hash functions published by NIST.

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Issue regarding installation of SHA256 scertificate

Can anyone help me with the installation of SHA256 certificate? I have generated the certificate perfectly but there seems to be an error below: Kindly let me know why am getting the exclamation ...
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0answers
37 views

How do I decrypt a RSA-SHA1 code? [on hold]

I am working on one project where I am having a RSA-SHA1 modulus code and Exponent value only. which is as follows: Modulus: ...
1
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1answer
60 views

Browser response to SHA1 signed cert

Generated a IIS server certificate using my domain certificate authority (presumed to be an intermediate to the 'secret' root CA) via the Server Certificates -> Create Domain Certificate 'wizard'. ...
2
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2answers
80 views

Why is it fine for Certificates above the end-entity certificate to be SHA1 based?

I have heard about the phasing out of Sha1 based certificates for end entity use, and the steps that are outlined for chrome to display progressively more aggressive warnings for Sha1 certs not ...
61
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3answers
6k views

Why is Google still using a sha1 certificate on its own site when they are phasing them out in Chrome?

Firefox dev tools shows that https://www.google.com is using a certificate signed with SHA1. Why is Google doing this when they are phasing out the certificate themselves? Shouldn't this only hurt ...
3
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2answers
255 views

Obsolete cryptography (SHA1) warning although certificate uses SHA256

I ordered a certificate with SHA256 from Comodo and was wondering why Chrome shows this message: Your connection is encrypted with obsolete cryptography. The connection is encrypted using ...
0
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0answers
29 views

SHA-2 migration considerations

due to SHA-1 being in the path of deprecation, i will be migrating my SSL certs to SHA-2. Besides creating CSR using SHA-2 for signing, what other considerations should I take note of? I believe one ...
4
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1answer
94 views

Why did browsers deprecate 1024-bit RSA, but retain SHA-1?

I was reading Mozilla's security blog Phasing out Certificates with 1024-bit RSA Keys. Effectively, some browsers are deprecating 1024-bit RSA for CAs and Subordinate CAs because the certificate must ...
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1answer
65 views

Is it worth it to implement both SHA2 and SHA3 at the same time?

I'm creating a password storage system for a web server I'm building for fun. Would it be more secure for me to use both SHA2 and SHA3 for hashing, and then store them in a database? If I use both ...
5
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1answer
4k views

Firebug reports SHA-1 certificate error

For the script at the bottom of this post, Firebug reports the following error: This site makes use of a SHA-1 Certificate; it's recommended you use certificates with signature algorithms that ...
6
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4answers
1k views

Store password using sha1 [duplicate]

I've been using the sha1() function to hash password before inserting it into my database. But I have this procedure so that it just won't be the password to be hashed. My page would register a user ...
32
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2answers
3k views

What is the relationship between “SHA-2” and “SHA-256”

I'm confused on the difference between SHA-2 and SHA-256 and often hear them used interchangeably (which seems really wrong). I think SHA-2 a "family" of hash algorithms and SHA-256 a specific ...
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0answers
80 views

how many sha1 hashes per time on current hardware [closed]

How many sha1 hashes per second can current hardware (say a 500$ gpu) compute, when the input is 256 byte long? (or any other length). The question behind is how long (or how costly) is it to mount a ...
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0answers
67 views

How does SHA3 (Keccak & SHAKE) compare to SHA2? Should I use non-SHAKE parameters?

Keccak is the winner of the SHA3 competition. Since Keccak is highly customizable (presumably for security/memory/time/speed tradeoffs) there does seem to be some controversy around how Keccak ...
2
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1answer
95 views

Securely storing passwords using PHP5

Starting note: After going through some articles and answers posted on SO related to storing secured passwords I'm still not sure whether my way of thinking is applicable to todays reality. I'm ...
3
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2answers
138 views

Is there any reason for using private key 2 times when creating security hash?

One of the payment solutions for the websites provides the following way of creating security hash for payment link: hash = sha1(private_key + payment_params_json + private_key); Is there any ...
0
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2answers
133 views

Is my hashing function good enough

Is there an obvious flaw with this hashing function (written in PHP)? function hash($password) { sleep(1); // Make hashing slow $hash = ""; $iterations = strlen($password); for ( $i = 0; $i ...
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1answer
82 views

Disastrous aftereffects of a hashing attack

I am writing about hashing functions for my thesis. I want to know whether there were disastrous aftereffects of a successful hashing attack in history and what kind of hashing attack was used. ...
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2answers
78 views

Is it known to what message size are standard hash functions injective?

This simple Python script verifies that all messages of length 1 have different SHA-1 hashes: import hashlib s = set() for i in range(256): s.add(hashlib.sha1(chr(i)).hexdigest()) print len(s) ...
0
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1answer
73 views

What is the risk of using SHA1 in PGP email signatures?

SHA-1 is being phased out by a lot of major companies due to vulnerabilities. For example Chrome no longer considers it safe for public web PKI. Is it insecure to use SHA-1 for PGP email signatures?
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0answers
28 views

In DNSSec, are Delegation Signer Records always SHA-1?

I'm creating a RSA/SHA-512 Zone Signing Key and Key Signing Key at Dynect Managed DNS (corporate offering) The Delegation Signer Record that was created is SHA1. Should I be concerned about this?
5
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2answers
249 views

How is a hash's algorithm detected based on the hash?

I was reading an Ars Technica article this morning and came across the following towards the end (emphasis mine): Equation Group included six other hashes in different exploits that remain unknown ...
2
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1answer
101 views

Truncating hash output for a unique ID

This seems like a common question, but my knowledge on hashing is very limited, so I'm looking for a more ELI5-type answer. I would appreciate if someone could help me with my questions Some ...
0
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1answer
89 views

Signature scheme using RSA and SHA512

What do you think about this signature scheme using RSA with 4096 bit keys? Being R pseudorandom padding, fixed length (4096 - 512 bits): RSApriv(R || SHA512(M)) I know that it's not as secure as ...
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2answers
118 views

About SHA1 in default Disk Encryption in Linux

Link to the Thread: Recommended options for LUKS (cryptsetup) I wonder what's the exact difference between SHA1 and SHA512. I know that SHA512 has a longer key but I've read that it doesn't matter ...
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2answers
130 views

HMAC and non-repudiation

This was a question on an exam: Two persons are using a one way communication channel and the HMAC functionality (concretely HMAC-SHA1). Choose the correct statement below: 1) We can prove who the ...
5
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2answers
2k views

Security of Linux Full Disk Encryption (Ubuntu / Mint) -insecure?

I'm wondering, why is Ubuntu and Mint using SHA1 for Full Disk Encryption? I heard several times that SHA1 shouldn't be used anymore because it is weak and it could be cracked. Could you guys ...
11
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1answer
619 views

Torrent “bad seed” attack by Sony, how does it work?

Sony recently saw a large amount of data stolen. In order to prevent the stolen data from being spread using torrents, they are doing what was called a bad seed attack. What is this attack? Is this a ...
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3answers
4k views

Is Git crowdsourcing cryptographic attacks?

A strong cryptographic hash makes collisions unlikely. Many cryptographic protocols build on that fact. But Git is using SHA-1 hashes as object identifiers. So there are a lot of already computed ...
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2answers
121 views

SHA1 - S/MIME and CRL validity after deprecation?

In an internal PKI using SHA1 for hashing, will S/MIME signature and CRL/ARL signature be considered invalid in the next few years (SHA1 Deprecation) ? End certificates can be revoked, CA ...
2
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0answers
108 views

Is this PHP TOTP (time based one time password) idea sound?

Disclaimer: I am not very familiar with safety techniques in general. The problem: Quickly create lots of small files in server from a bash script. I used to use scp (secure copy) in order to create ...
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2answers
1k views

nginx recommended ssl_ciphers

I am looking for some advice on setting the ciphers for nginx with SSL. What would you recommend for a good compromise between security and compatiblity at the moment? I have made some research but ...
7
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1answer
641 views

Is there a method to get plain-text from cipher-text in HMAC SHA-1, given that the key is known?

This is technically not even an attack. We have all the resources at hand, except for the original plain-text. We have the cipher-text (to be converted back to plain-text), as well as the key. The ...
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1answer
246 views

How will SHA1 deprecation affect SHA1 roots in OS/Browser trust stores.

I understand the SHA1 deprecation policy applies to CA's issuing SHA2 end-entity certs and intermediates starting Jan 2017 but how will this policy affect the actual root certificates in OS/Browser ...
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2answers
110 views

Should I use HMAC in this situation

I need to store a big message encrypted on a server. What I am about to do is: Encrypt the message with a AES key; (Authentication) Hash the message with SHA512 and encrypt the hash with RSA priv ...
0
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1answer
217 views

Why are CA's now signing root certs with SHA2?

I see that CA's are now giving the option of having the root CA cert signed with SHA2. I have been told that the hashing function in a root has no security value, and is irrelevant as far as a ...
2
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3answers
164 views

GPG keys & SHA-1

I've heard that SHA-1 hashing is becoming less secure, and that most GPG keys are secured with SHA-1. Is there a way to determined if SHA-1 is in my GPG key, and what to do if this is the case?
14
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2answers
790 views

How safe are signed git tags? Only as safe as SHA-1 or somehow safer?

How safe are signed git tags? Especially because git uses SHA-1. There is contradictory information around. So if one verifies a git tag (git tag -v tagname), then checksouts the tag, and checks that ...
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2answers
228 views

What does 2^77.1 calls presented in a SHA1 attack mean?

Regarding the SHA 1 deprecation, I found this information here: http://blogs.technet.com/b/srd/archive/2013/11/12/security-advisory-2880823-recommendation-to-discontinue-use-of-sha-1.aspx I know ...
4
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1answer
198 views

How will SHA1 deprecation affect internal CA's?

I am hearing that the SHA1 Deprecation notices from MS/CHROME only apply to certs that are a part of a public trusted root program. This makes one believe that IE will have new logic built in to allow ...
13
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3answers
1k views

Trying to understand why signatures in root certs “are not used”?

Taken from here: Don't worry if the root certificate uses SHA1; signatures on roots are not used (and Chrome won't warn about them. Why are the signatures not used? Are not root certificates ...
18
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3answers
4k views

Is SHA1 weak for SSL?

I noticed that today after I scanned a site on the Qualys SSL Labs site that SSL ciphersuites which use SHA1 are now highlighted as being "Weak". It seems this has just happened; I scan sites pretty ...
2
votes
1answer
403 views

Python implementation of AES and SHA256/512 that are FIPS-140-2 validated?

For security purposes I need to use AES encryption and SHA256/512 in my Django/Python project. I know there are various libraries out there that provide different encryption methods but I can't seem ...
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2answers
244 views

Why is the brute force search time for hashing algorithms 2^(num_bits / 2)?

I noticed that the brute force times (the time it takes to find a message that hashes to a given hash) of various hashing algorithms seems to be 2^(num_bits / 2). For example, people say that brute ...
2
votes
1answer
291 views

HMAC secret key for securing communication - how to keep private on DB

I have a mobile app that communicates to server over HTTPS. To authenticate the client and to make sure its who I believe it is, I return upon successful signup (apart from the username) a secret API ...
2
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3answers
321 views

Does figuring out what one password hashes to allow you to crack all identical passwords?

Forgive me, as I am very new to cryptography, but it seems interesting, and I have a question. I'll state my beliefs and please feel free to correct me on the aspects that I'm mistaken so i can ...
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4answers
105 views

Confidentiality of file hashes

Context: I have a directory full of sensitive company files. I want to compare these files with a colleague at a remote location, without the need for a secure connection. Is it safe for me to ...
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49 views

How is this SHA-1 hash generated? [closed]

If you get a disposable email from say guerrillamail.com, and then fill out the forgot my password page at dahorta.org/app/index.php/cliente/resgatar_senha, it emails you a link to reset your ...
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3answers
185 views

Did the “Malicious SHA-1” technique enable the NSA to insert a backdoor into SHA-1?

SHA-1 was standardized by the NSA. It appears to be possible to choose the constants in such a way that collisions can be derived easily. Yet, it is not easily possible to discover that the constants ...
0
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1answer
87 views

Is it possible to distinguish between a SHA256 hash and an ecc256 key?

If an attacker were just given 256 bits, and they were either a SHA256 hash or a 256 bit elliptic curve key, would they be able to tell which one it is? Just out of curiosity, would they be able to ...