Comparison

SKI+ v2 vs Post Quantum Secure Chat

Price, ratings, monetisation and update history for both apps, side by side โ€” with what reviewers say about each.

Head to head
About

SKI+ v2

Features
Read full description

SKI+ v2 is an end-to-end instant messaging app with in-depth support of post-quantum encryption algorithms. Message encryption and decryption are completed on the user's device, and the server has no access to these details. Therefore, it provides users with a more privacy-protected messaging system. For more details, please refer to https://www.e2eelab.org. Feel free to download and use it. If you have any questions or suggestions, please send relevant descriptions or screenshots to: ziv@citi.sinica.edu.tw. We will address your inquiries promptly.

About

Post Quantum Secure Chat

Features
Read full description

Secure messaging for the quantum era. PQC Chat is the first consumer messaging app built with NIST-standardized post-quantum cryptography. While traditional encryption may be vulnerable to future quantum computers, PQC Chat uses ML-KEM-768 and ML-DSA-44 algorithms to ensure your private conversations remain private โ€” today and tomorrow. Why Post-Quantum Security Matters Quantum computers pose a real threat to current encryption standards. Data encrypted today could be stored and decrypted later when quantum computers become powerful enough. PQC Chat protects you against this "harvest now, decrypt later" threat. Key Features โ€ข True End-to-End Encryption โ€” Messages are encrypted on your device and can only be read by the intended recipient. Not even we can access your conversations. โ€ข NIST-Approved Algorithms โ€” Built with ML-KEM-768 for key exchange and ML-DSA-44 for digital signatures, the same standards adopted by governments worldwide. โ€ข Secure Image Sharing โ€” Photos are encrypted before leaving your device, ensuring complete privacy for all shared media. โ€ข QR Code Contact Verification โ€” Verify contacts in person by scanning QR codes, preventing man-in-the-middle attacks. โ€ข Real-Time Messaging โ€” Instant message delivery with read receipts and typing indicators. โ€ข No Phone Number Required โ€” Create an account without sharing personal information. โ€ข Cross-Platform โ€” Message friends on any device seamlessly. Privacy by Design - No message content stored on servers - No tracking or analytics - No ads, ever - Open cryptographic standards About Post-Quantum Cryptography PQC Chat implements the Federal Information Processing Standards (FIPS) 203 and 204, published by the National Institute of Standards and Technology (NIST) in August 2024. These represent the gold standard in quantum-resistant cryptography. Protect your conversations for the future. Download PQC Chat today. Terms of Use (EULA): https://pqcnow.com/terms-of-service

Screenshots

SKI+ v24 screens
Post Quantum Secure Chat4 screens

Verdict

The call

The clearest difference is in-app purchases: SKI+ v2 at none against Post Quantum Secure Chat's 2. Post Quantum Secure Chat's advantage is iOS requirement (13.0 vs 17.6). On price, update cadence, ads and device support there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. Post Quantum Secure Chat sells 2 in-app purchases, starting at $4.99 per month. SKI+ v2 asks for nothing beyond the download.

UpkeepUpdate frequency

SKI+ v2 ships an update fortnightly, Post Quantum Secure Chat every 10 days. The most recent releases landed on September 10, 2026 and September 6, 2026 respectively.

Scorecard2 real differences ยท 4 level
SKI+ v2 versus Post Quantum Secure Chat: the parameters behind the verdict, then further details
ParameterSKI+ v2Post Quantum Secure Chat
PriceFreeFree
Update frequencyFortnightlyEvery 10 days โ€” better
AdsNoNo
In-app purchasesNo โ€” betterYes
DevicesiPhone, iPadiPhone, iPad, iPod โ€” better
Requires iOS17.613.0 โ€” better
Further details โ€” not scored
Size249 MB35 MB
Age rating4+4+
DeveloperAcademia Sinica Research Center for Information Technology InnovationSAYMATIK BILISIM VE TEKNOLOJI ANONIM SIRKETI

In-app purchases

None

SKI+ v2

No in-app purchases

2 purchases

Post Quantum Secure Chat

Subscriptions2
  • Monthly Subscription$4.991 Month
  • Annual Subscription$29.991 Year

Questions

Is SKI+ v2 free?
SKI+ v2 is free to download, with no in-app purchases.
Is Post Quantum Secure Chat free?
Post Quantum Secure Chat is free to download, with in-app purchases available.
Do SKI+ v2 or Post Quantum Secure Chat have ads?
Neither SKI+ v2 nor Post Quantum Secure Chat shows ads.
Which is updated more often, SKI+ v2 or Post Quantum Secure Chat?
SKI+ v2 ships an update fortnightly, and Post Quantum Secure Chat every 10 days. Most recently, SKI+ v2 was updated on September 10, 2026 and Post Quantum Secure Chat on September 6, 2026.

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