Sha1 collision ctf. If no one is trying to generate collisions in your hash .
- Sha1 collision ctf. We show that collisions of SHA-1 can be found with complexity less than 269 hash operations. Let’s introduce briefly SHA-1: it is a hash function created in the early 90s and standardized by NIST in 1995. Sep 23, 2021 · 以前書いた記事 GitのオブジェクトID衝突時の挙動 に頂いたコメントで、GitにSHA-1衝突攻撃検出のライブラリ sha1collisiondetection が組み込まれていることを知った。 OpenSSLと類似のインタフェースで使えるのを実際に試してみた。 テストデータ ライブラリのソースをcloneしてくると、テストデータも Apr 9, 2022 · 来源： sha 1 - SHA1 collision for first 32 bits for two different messages - Cryptography Stack Exchange 这只是一个弱碰撞， abc123_owlstead_1255 和 abc123_owlstead_59131 的前32位哈希值相同。 Jul 29, 2017 · We are the first to exhibit an example collision for SHA-1, presented in Table 1, thereby proving that theoretical attacks on SHA-1 have now become practical. Slides A key reason behind the reluctance of many industry players to replace SHA-1 with a safer alternative is the fact that nding an actual collision has seemed to be impractical for the past eleven years due to the high complexity and computational cost of the attack. but first, we need to know the hashing algorithm. Contribute to corkami/collisions development by creating an account on GitHub. Collisions in the MD5 cryptographic hash function It is now well-known that the crytographic hash function MD5 has been broken. Full guide with steps. Collisions necessarily exist, since SHA-1 accepts many more distinct messages as input that it can produce distinct outputs (SHA-1 may eat any string of bits up to 2^64 bits, but outputs only 160 bits; thus, at least one output value must pop up several times). It is widely used in cryptocurrency and other security applications. The code is written in Python 3. cn/6423 php弱比较等一些问题的总结 另一个总结 php漏洞汇总 自动化解析 判断题目特征： web php md5 collision 设定题目难度等级 level 为simple 提交相应符合要求的字符串 Dec 23, 2023 · 本文介绍了CTF比赛中关于MD5加密的两种比较类型：弱比较和强比较。对于MD5弱比较，通过0e科学计数法的特性来绕过字符串与字符串、字符串与整数的比较；而对于强比较，可以通过数组绕过或寻找特定的MD5碰撞字符串。同时，提供了Python脚本用于生成特定形式的MD5字符串，以解决实际解题中遇到的 Mar 31, 2019 · This time, we will calculate each file’s SHA1 hash. Oct 18, 2019 · Balsn CTF 2019 - Collision (crypto). Oct 15, 2024 · Capture the Flag Competition WikiHashing Functions Hashing functions are one way functions which theoretically provide a unique output for every input. The main topic of this chapter is the development of practical chosen-prefix collision attacks and their applications. ) was the first ever practical and public SHA-1 collision between two PDF files. Jan 8, 2025 · On the other hand, despite the known collision in the SHA1 function and the recommendation not to use it, it is still more widely used. Due to the pigeonhole principle (where we're mapping an infinite input space to a finite output space), collisions are mathematically inevitable - the question is not if they exist, but how hard they are 碰撞攻击取决于hash算法的强度，像是MD5和 SHA-1 这些hash算法已经被证明是不安全的，可以在很快的时间内被攻破。 选择前缀冲突攻击 除了前面传统的碰撞攻击之外，还有一种叫做 Chosen-prefix collision attack 选择前缀冲突攻击。 Dec 11, 2017 · はじめに この記事は、SECCON 2015 Online CTFの問題集が公開されているので 、後追いで、勉強がてら調べながらやってみた記録になります。 SECCONという楽しそうなものがあるらしいというのを丁度2015年の年末に知った、ただの謎解き好きの挑戦記録のため、超初心者目線です。 近い将来 Feb 22, 2012 · How would Git handle a SHA-1 collision on a blob? Asked 13 years, 4 months ago Modified 3 years, 8 months ago Viewed 88k times Nov 23, 2020 · 2020 SCIST Web Week 2 2020 SCIST Web Week 2 Web SSRF NOOB Level 1 HTTP Method Level 2 sha1 collision Md5 collision Download Level 3 New HTTP Method sh3ll_upload3r ImageUploader Level 4 Kaibro_easy-pickle To serialize or Not to serialize //TODO ImageUploader2 Ev41 協作者 Web SSRF NOOB 首先進入網站 只有一個輸入的框框 give me the url 輸入看看這題的網址 看起來 In particular, we have a chosen-pre x collision attack against SHA-1 with complexity between 266:9 and 269:4 (depending on assump-tions about the cost of nding near-collision blocks), while the best-known attack has complexity 277:1. Bitcoin uses SHA-256, not SHA-1 to my knowledge which is much safer. Jun 28, 2023 · SHA-256: This is a more secure version of the SHA-1 hash function and generates a 256-bit hash value. This script provides two strings with the same SHA1 value that has the same suffix as input. io This Cheatsheet will be updated regularly When you are trying to solve a Crypto Challenge for a CTF, first of all, you need to detect which Cipher is used. 0 level1 - gitcoin miner) - miner. Collection of write-ups regarding Crypto CTF. io we see that it is possible for 2 different PDF files to have identical SHA1 hashes. The way MD5 hashes are created, any slight variation in a file creates a new hash that is completely different than the previous Feb 27, 2017 · Using the SHA1 collision attack to solve the BostonKeyParty CTF challenge Posted by Infosec Shinobi | Posted in Security Articles | Posted on 27-02-2017 Sep 6, 2019 · 本文介绍了一个Python脚本，用于解决CTF竞赛中特定的hash碰撞问题。 通过SHA1算法，脚本搜索并输出前五位为903ed的hash值对应的数字。 Oct 31, 2020 · https://github. For example if it’s a Symmetric or Asymmetric cipher, a Classic cipher or if it Sep 23, 2019 · 由此推廣的一般性問題，就是具 collision resistance 的 hash function 能處理多少筆輸入，而不用擔心有 collision？ 比方說 SHA-256 的輸入最大可到 2⁶⁴-1 bits Jan 3, 2025 · 文章目录 前言 一、md5算法 MD5算法底层原理 二、md5值相等绕过原理 常见的md5值是0e开头的且后面均为数字的字符串 例题，ctfshow，web5 三、数组绕过（PHP8无法绕过） 四、md5碰撞 基本用法 举个栗子 I have been trying to understand exactly how a length extension attack works on SHA-1. Keywords: Hash functions, collision search attacks, SHA-1, SHA-0. txt in this repo) provides source code of both server PHP and client HTML part. Starting today, all SHA-1 computations on GitHub. Near-collision attacks. If you are interested in Crypto check out crypto101. Our work builds upon the best known theoretical collision attack [43] with estimated cost of \ (2^ {61}\) SHA-1 calls. In fact, it’s more secure to use SHA-256 (256 bits long) than a combination of md5 and SHA-1 (totaling 288 bits). In March 2005, Xiaoyun Wang and Hongbo Yu of Shandong University in China published an article in which they describe an algorithm that can find two At the rump session of CRYPTO 2004, Xiaoyun Wang and co-authors demonstrated a collision attack against MD5 [1]. In a nutshell, this means a complete and practical break of the SHA-1 hash function, with dangerous practical implications if you are still using this hash function. A key reason behind the reluctance of many industry players to replace SHA-1 with a safer alternative is the fact that nding an actual collision has seemed to be impractical for the past eleven years due to the high complexity and computational cost of the attack. 4k次。本文介绍了一种通过穷举法找到特定MD5散列对应的4字符明文的方法，并进一步计算该明文的SHA256散列值以获取最终的FLAG。文章详细展示了使用Python进行散列计算的过程。 What do I choose if I want a faster function and collision on random data near to SHA-1? Maybe a 128 bit hash is good enough for file deduplication? (vs 160 bit sha-1) In my program the hash is calculated on chuncks from 0 - 512 KB. wad Size 46. SHAttered (by Stevens et al. Why hasn't' this happened? Apr 19, 2023 · 文章介绍了CTF中关于MD5绕过的几种方法，包括利用PHP的0e漏洞进行哈希碰撞。讨论了PHP的类型比较，如松散比较和严格比较，并提供了实际的题目示例，展示如何在不同比较条件下构造有效载荷来绕过校验。此外，还涉及到了SQL注入与MD5结合的解题技巧。 SHA-1 算法对首先将文件分成 512 bit 的 block（不足的 block 通过特定算法补足）。 观察之后的计算算法可发现，只要前面的 block 已经发生碰撞，之后添加相同的区块一定能得到相同的结果。. It is to do with SHA1, a hashing algorithm, which for the first time has a collision been found. exe sticks out like a sore thumb with its different SHA1 sum. In this paper, we demonstrate that SHA-1 collision attacks have nally become practical by providing the rst known instance of a In this paper, we present new collision search attacks on the hash function SHA-1. com) 题目源码： Mar 20, 2017 · 最近，ハッシュの一種であるSHA-1について，米Googleが初めて衝突に成功させたということが話題になりました．その衝突ハッシュを使った衝突例として，SHA-1の一致する二つのPDFを作成していました． その方法について説明されている資料があったので自分でもSHA-1を衝突させたPDFを作成してみ Magic hashes – PHP hash "collisions". Exactly how expensive is what we’ll try to answer in today’s blog post. Jan 9, 2020 · SHA-1使用情况 在最近几年，SHA-1的使用已大大减少；尤其是Web浏览器现在拒绝使用SHA-1签名的证书。 但是，许多应用程序仍支持SHA-1签名。 SHA-1是用于在GnuPG的旧有分支中认证PGP密钥的默认哈希函数，签名已被GnuPG的现代分支所接受。 Filenames zdmegactf-1d. The way the code works is this: random hashes git fatal: SHA1 COLLISION FOUND Asked 11 years, 1 month ago Modified 7 years ago Viewed 20k times Contribute to maojui/Crypto-CTF-Cheatsheet development by creating an account on GitHub. Based on what I was reading about juggling, when comparing two strings starting with "0e" followed by numbers, the comparison is true, no matter if the string is different, it is always true. SHA1 基本描述 SHA1 的输入输出如下 输入：任意长的消息，分为 512 比特 长的分组。首先在消息右侧补比特 1，然后再补若干个比特 0，直到消息的比特长度满足对 512 取模后余数是 448，使其与 448 模 512 同余。 输出：160 比特的消息摘要。 关于详细的介绍，请自行搜索。 一般来说，我们可以通过函数的 Dec 11, 2016 · Crypto 101 This is a beginner guide, not an Academic paper Also this is very summary and CTF-specific. This could be mitigated by recording the hashed values. Feb 28, 2017 · This is a writeup to the Boston Key Party CTF 2017 Prudential challenge – which I took part in over the weekend. 95 MB MD5 bed62338d856ce8f985a5466a94ec042 SHA-1 c4ef472ac95bd3d56ed83a083428d900ebf9b65f SHA-256 WAD Type IWAD Engines Unknown Jun 9, 2020 · Is a CTF challange. This is the first Apr 24, 2022 · It really depends why you’re hashing and what the consequences of a collision are. it/). 散列值的目的如下 确保消息的完整性，即确保收到的数据确实和发送时的一样（即没有修改、插入、删除或重放），防止中间人篡改。 冗余校验 单向口令文件，比如 linux 系统的密码 入侵检测和病毒检测中的特征码检测 目前的 Hash 函数主要有 MD5，SHA1，SHA256，SHA512。目前的大多数 hash 函数都是迭代 261 2 61 hashes, per Marc Stevens: New collision attacks on SHA-1 based on optimal joint local-collision analysis (in proceedings of Eurocrypt 2013, also freely available from the author's website). The purpose of this CTF is to find the specific string that meets those conditions. Apr 21, 2022 · In particular, we remark that the chosen-prefix collisions for SHA-1 can be generated in under a minute, with an ASIC cluster that costs a few dozen Millions dollars. This is an identical-prefix collision attack, where a given prefix P is extended with two distinct near-collision 3. That means SHA1 is dead officially. Intro: hash collisions Let’s introduce briefly SHA-1: it is a hash function created in the early 90s Jul 17, 2018 · Recently a team of researchers generated two files with the same SHA-1 hash (https://shattered. Contribute to spaze/hashes development by creating an account on GitHub. Since Git uses this hash for its internal storage, how far does this kind of attack influence Git? Oct 27, 2017 · The popularity of SHA-256 as a hashing algorithm, along with the fact that it has 2 256 buckets to choose from leads me to believe that collisions do exist but are quite rare. While we implemented the attack and verified it, our best result at the moment is a 4-bit near collision, which is to date, the best known near-collision against SHA3-384. So, we need to find the sha-1 of the hash result. Suppose an executable file format consisting of : 4-byte magic value 0x4D6F4546 (My own Executable Format) Jan 1, 2005 · In this paper, we present new collision search attacks on the hash function SHA-1. To put it in another way: all attacks that are practical on MD5 are now also practical on SHA-1. Check our paper here for more details. 4 and uses the sha function from the hexlib library to search for collisions. It is very, very unlikely that the odd file will have an identical MD5 and SHA1 hash value as the other files. A historical overview of the identical-prefix and chosen-prefix collision attack costs for MD5 and SHA-1 can be found in Tables 1 and 2. Hash collisions and exploitations. A 128 block cypher will produce the 1:1 mapping but requires the key be secret for ever (or changed peridically) There Yesterday one of my team's checkins corrupted our github repo. I imagine this can also be done where the input is a large file and you just change one byte and calculate the hashes until you find a collision. We can use this website to identify the hashing algorithm. g. . Chosen-prefix collisions are usually significantly harder to produce than (identical-prefix) collisions, but the Jan 31, 2025 · Who got a new GPU? First things first, if you’re still using the SHA-1 hashing algorithm in 2025, you are probably doing something wrong, or hopefully working on a very expensive Capture-the-flag (CTF) challenge. Because of the way SHA1 works, we can start off by using the first 5 blocks from SHAttered, and then if the rest of the files have identical content, their hashes will be the same. 解题步骤 输入参数 $a=240610708 得到flag 漏洞挖掘思路 由于php比较符智能 转换 导致的问题：http://www. Contribute to cr-marcstevens/hashclash development by creating an account on GitHub. This system is commonly used to check the integrity of files (like downloads). Contribute to firmianay/CTF-All-In-One development by creating an account on GitHub. Contribute to v95heldon/Crypto_CTF_writeups development by creating an account on GitHub. 禁用数组-sha1强比较绕过 群里师傅问的一道题目，正好之前马了相关文章，很有意思但没复现过，借此机会水一篇博客 参考文章： ctf/Prudentialv2_Cloud_50. So, security experts usually use a single long hash, like SHA-256 or SHA-3. If no one is trying to generate collisions in your hash Jun 26, 2025 · TryHackMe Fortress Walkthrough: Reverse Python bytecode, crack SHA-1 collision, bypass login, escalate via sudo, and root the box. Such ability would allow an attacker to apply the SLOTH attack on TLS or SSH connections using SHA-1. On github, they were showing this error: $ git fsck error: sha1 mismatch Suppose i assume if hash collision occur while i am using sha1 function in php . Apr 24, 2022 · 这篇博客记录了CTF比赛中常见的MD5碰撞现象，重点介绍了以0e开头的MD5值，并列举了一系列对应的原文字符串，这些碰撞在Web安全领域中具有一定的实践意义，适合对渗透测试和代码审计感兴趣的读者学习。 Feb 28, 2017 · This is a writeup to the Boston Key Party CTF 2017 Prudential challenge – which I took part in over the weekend. Furthermore, PHP will honor "exponential notation" when evaluating integers. I find that showing collisions to people I'm explaining hashing to is a great way to show them what non In case anyone's curious or confused, this does not have to do with any Bitcoin flaw. md at master · bl4de/ctf (github. In this paper, we demonstrate that SHA-1 collision attacks have nally become practical by providing the rst known instance of a Hash Collisions: Understanding the Fundamentals What is a Hash Collision? A hash collision occurs when two different inputs produce the same hash output when processed through a hash function. SHA-1 is a Shambles We have computed the very first chosen-prefix collision for SHA-1. I manage to commit two files with the same sha1 checksum, would git notice it or corrupt one of the files? Could git be Mar 27, 2024 · twitter. SHA1 collision by SHATTERED attack This is a simplified interface from sha1collider. Mar 18, 2024 · For instance, hash functions like MD5 and SHA-1, which lack collision resistance, are particularly susceptible. But for this challenge, it has to have the same last 1000 bytes as the original invite. This is within a small factor of the complexity of the classical collision attack on SHA-1 (estimated as 264:7). To identify hash functions vulnerable to Length Extension Attacks, we follow these steps: The expected running time of this attack is below 260 (we remind the reader that the SHA1 collision found by [27] used about 263 computation). Feb 17, 2016 · I am trying to find two collisions in SHA1 for the 50 least significant bits. Are there any well-documented SHA-256 collisions? Or any well-known collisions at all? I am curious to know. com/jedisct1 179 points by devStorms on March 27, 2024 | hide | past | favorite | 60 comments Aug 25, 2022 · 文章浏览阅读1. As description mentioned Prudential challenge from two years earlier, I immediately went to my CTF writeups repository and found this one (Boston Key Party 2015): https Jan 4, 2019 · A few weeks ago, researchers announced SHAttered, the first collision of the SHA-1 hash function. Bitcoin only acts as a reward for finding the collision. It is my birthday This challenge is regarding a SHA-1 collision on PDF documents. MD5, SHA-1, and other hashes which were considered secure are now found to have collisions or two different pieces of data which produce the same supposed unique output. In February 2017, CWI Amsterdam and Google Research announced the SHAttered at-tack, which breaks the collision-resistance property of SHA-1 [3]. txt (see prudentialv2. So We First need to find the hash result. com) Using the SHA1 collision attack to solve the BostonKeyParty CTF challenge (linkedin. Oct 1, 2004 · PHP is a popular general-purpose scripting language that powers everything from your blog to the most popular websites in the world. It is not a weakness in the hash function's distribution. Feb 27, 2017 · Tweet Sumo This is a writeup to the Boston Key Party CTF 2017 Prudential challenge – which I took part in over the weekend. String Hashing A string hash is a number or string generated using an Website contains simple HTML form with two standard fields for username and password. I was wondering if there was a way to efficiently do this without having to brute force all of the possible hash outpu There is an example in Collision Search Attacks on SHA1 paper by Wang, Yin and Yu, from 2005, but just for weakened, 58-round version of SHA-1. (The full, official SHA-1 performs 80 rounds. Mar 30, 2022 · 本文介绍了一种利用特殊构造的数据来解决PHP中强MD5碰撞问题的方法。通过具体实例展示了如何绕过强类型比较（===），并给出了适用于md5 ()和sha1 ()的有效payload。 May 10, 2019 · Paper 2019/459 From Collisions to Chosen-Prefix Collisions - Application to Full SHA-1 Gaëtan Leurent and Thomas Peyrin Abstract A chosen-prefix collision attack is a stronger variant of a collision attack, where an arbitrary pair of challenge prefixes are turned into a collision. Overview, Concept and Design Criteria This challenge is inspired by some real world applications that use both sha256 and crc32 for password hashing, which totally ruined sha256. Looking at the hint shattered. 124 What you describe is called a collision. It was kinda 'déjà vu' for me. bugku of md5 collision (NUPT_CTF) Topic Link The tips are subject to md5 Page to enter a prompt is please input a That is a loophole md5 PHP when processing the hash string, will use "! =" Or "==" to compare the ha MD5 Collision Demo Published Feb 22, 2006. Using a hashing algorithm to protect sensitive data (should I hash passwords with SHA-1?) should weight the value of this answer significantly differently than using it as a convenient lookup optimization (should I use SHA-1 to identify git references?). com will detect and reject any Git content that… We have a corrupted hash password and a note that says that the password is the sha-1 of the hash result. 9K votes, 327 comments. This challenge requires a specific hash parameter sent by GET. Nov 2, 2023 · 哈希长度扩展攻击 Message Authentication Codes Message Authentication Codes (MACs)是用于验证信息真实性的算法。最简单的MAC算法是这样的：服务器把key和message连接到一起，然后用摘要算法如 MD5 或 SHA1 取出摘要。例如有一个网站，在用户下载文件之前需验证下载权限。这个网站会用如下的算法产生一个关于文件 Project HashClash - MD5 & SHA-1 cryptanalysis. we all know that there is a minor risk of collision and the risk reduces (not complet… How has a collision never been found? If I decide to find the hash for a random input of increasing length I should find a collision eventually, even if it takes years. The type of collision they created was a fixed-prefix collision: A collision created by having identical starts of files, followed by distinct, slight differences in a small amount of the files Google公司和诸多IT安全研究人员均在过去几年呼唤开发者尽快更换SHA-1算法，早在2014年，Chrome团队就已经宣布了淘汰SHA-1算法的时间表，本次碰撞实例的发布，也给所有还在持观望和犹豫态度的人敲响了警钟：赶紧为安全的系统启用新的Hash算法！ Oct 23, 2010 · The result announced in your link is an attack, a sequence of careful, algorithmically-chosen steps that generate collisions with greater probability than would a random attack. /r/netsec is a community-curated aggregator of technical information security… The following summary is adapted from cs-ahmed/Hands-on-SHA1-Collisions-Using-sha1collider. collision md5 is broken, sha1 is broken, but our authenticator survives. This is the first attack on the full 80-step SHA-1 with complexity less than the 280 theoretical bound. GitHub Gist: instantly share code, notes, and snippets. c Gitbook: A big collection of my notes for Capture The Flag (CTF) challenges or Hacking in general - practical-ctf/cryptography/hashing/README. Using multiples hashes is 关于详细的介绍，请自行搜索。 一般来说，我们可以通过函数的初始化来判断是不是 SHA1 函数。一般来说，如果一个函数有如下五个初始化的变量，可以猜测该函数为 SHA1 函数，因为这是 SHA1 函数的初始化IV。 Nov 9, 2022 · Hello All, I understand that the MD5, SHA1 or SHA256 are some of the hash algorithms used for generating hash keys for business key. Last updated Oct 11, 2011. It takes two arguments: the first is the maximum number of random bytes to use as input to the hash function, and the second is the number of bytes needed, starting at the beginning of the hash, for two inputs to be considered a collision. vuln. ) A collision in SHA1 means that there were 2 sets of 5 blocks (320 bytes) found, that when SHA1 hashed give the same hash, while actually being different. I viewed the source of the webpage and found out an index. md at main CTF竞赛权威指南. A hash Oct 28, 2019 · CRYPT-5 消息认证和哈希函数 author : Odyssey@cyberpeace 消息认证 消息认证码（MAC） Hash函数 MD5哈希函数 安全哈希算法SHA-1 基于分组密码与离散对数的哈希函数 消息认证 消息认证的目标是：收到一条消息，希望确保消息在传递的过程中没有被改变 根据消息和秘密密钥生成一个短序列位 为了验证消息 一、哈希碰撞是什么？ 所谓哈希（hash），就是将不同的输入映射成独一无二的、固定长度的值（又称"哈希值"）。它是最常见的软件运算之一。 如果不同的输入得到了同一个哈希值，就发生了"哈希碰撞"（collision）。 举例来说，很多网络服务会使用哈希函数，产生一个 token，标识用户的身份和权限 MD5 Hashing MD5 is a widely used cryptographic hash function producing a 128-bit (16-byte) hash value, typically expressed in text format as a 32 digit hexadecimal number - Wikipedia. Hash Attack 常见的 Hash 函数的攻击方法主要有 暴力攻击：不依赖于任何算法细节，仅与 Hash 值长度有关； 生日攻击法 (Birthday Attack)：没有利用 Hash 函数的结构和任何代数弱性质，只依赖于消息摘要的长度，即 Hash 值的长度。 中点交会攻击法 (Meet-In-The-Middle)：是生日攻击的一种变形，不比较 Hash 值 This means that it will compute the regular SHA-1 hash for files without a collision attack, but produce a special hash for files with a collision attack, where both files will have a different unpredictable hash. This would hold even in a world where no flaws were found in md5 and SHA-1. com/oalieno/Crypto-Course/tree/master/HASH What would actually happen if I had a hash collision while using git? E. txt file was being referenced. Well, ok, it is, but not of the sort that makes a random attack likely on the order of 2^52 to succeed. 493K subscribers in the netsec community. In Linux, we can calculate the SHA1 hashes with “sha1sum *”. Snippets below: Feb 5, 2023 · Because of the weak comparison, PHP will try to convert string inputs (such as the SHA-1 hash) to integers. Method To solve this challenge, I first found 2 SHA1 colliding PDF from the internet (you can use a generator Sep 21, 2023 · Instead of using two 128 bits hashes (like md5), it is far more secure to use a single 256 bits hash. Generate git sha1 commit hash collision (used for Stripe CTF 3. 15832-3645-24173. I'll detail below what I've understood so far so that I can convey my understanding of the same and hopefully Jan 31, 2025 · First things first, if you’re still using the SHA-1 hashing algorithm in 2025, you are probably doing something wrong, or hopefully working on a very expensive Capture-the-flag (CTF) challenge. I think this has been answered by various respondees: sha-1 probably will produce collisions for the message space smaller than its digest size, there is certainly no gaurantee that it won't, but the odds are very small. index. bpoo qtpbm lqw ycjw zdxbki kabejfc gxwsit jgsu accxreo okeoye