PRELIMS
Two-Factor Authentication (2FA) and TOTP
Why in News: Growing cyber threats have made two-factor authentication (2FA) essential for securing online accounts. Popular methods like Google Authenticator use Time-based One-Time Passwords (TOTP) to generate short-lived numeric codes.
What is 2FA?
A security method requiring two proofs of identity:
- Something you know: Password.
- Something you have: Authenticator app/physical token.
Makes attacks harder as both password and device are needed.
One-Time Passwords (OTP)
- Short numeric codes, valid for a single use and within a short time (≈30 seconds).
- Prevent reuse → intercepted code becomes useless.
Time-based OTP (TOTP)
- Defined in open standards (RFC 6238).
- Uses secret key (shared) + time counter (30-sec intervals).
- Both server and app generate the same code for verification.
- Popular implementation: Google Authenticator.
How TOTP Works?
1. Service shares a secret key (often via QR code).
2. App + server use secret key + time counter.
3. Run through HMAC-SHA-256 (hash-based authentication code).
4. Apply dynamic truncation → reduces 256-bit output to 6-digit code.
5. Code changes every 30 seconds.
Key Cryptography Concepts
- Hash Functions: One-way, fixed-length outputs (e.g., SHA-256).
- HMAC: Combines secret key + message using hash securely.
- XOR Operation: Bitwise function, used in HMAC to mix key with “pads.”
Security Features
- Secret key stored only on device + server.
- Time-limited codes prevent reuse.
- Large cryptographic space makes guessing infeasible.
Alternatives to TOTP
- HOTP: Counter-based OTP (increments each use).
- Push-based 2FA: Approve login via phone notification.
- Hardware tokens: Devices like YubiKeys generate codes offline.
Himalayan Brown Bear (Ursus arctos isabellinus)
Why in News: Recently in news after an attack on Pakistani singer Quratulain Balouch in Deosai National Park, Gilgit-Baltistan. Incident highlights rising human–bear conflicts in the Himalayan region.
Ecology & Distribution
- Subspecies of the brown bear, less studied compared to North American/European relatives.
- Found in alpine and sub-alpine regions of north-western & western Himalayas (Ladakh, Himachal Pradesh, Gilgit-Baltistan).
- Population declining due to habitat fragmentation (deforestation, land-use change).
- Prefers low human density & minimal disturbance.
Impact of Climate Change
- Himalayas warming faster than global average (up to +3°C by 2100).
- Shrinks suitable habitats and alters food availability.
- Longer foraging season → bears move towards human settlements.
- Increases encounters and conflict risks.
Human–Bear Conflict
- Surging in Zanskar (Ladakh) & Lahaul valley (Himachal Pradesh).
- Bears raid livestock, crops; often drawn by food waste.
- Conflicts peak in autumn (hyperphagia phase) → bears fatten for hibernation.
- Recent years: economic losses reported; no major human fatalities.
Community Responses
- Increased sightings, livestock/crop damage reported.
- Poor awareness of bear behaviour + unregulated grazing worsen conflicts.
Suggested measures:
- Improved waste management.
- Controlled grazing.
- Community watch groups.
- Ecotourism + conservation integration.
Conservation Challenges
- Limited ecological data on the subspecies.
- Habitat protection alone insufficient → climate adaptation strategies needed.
Experts recommend:
- Protected zones in bear-rich areas.
- Sustainable land-use practices.
- Community involvement & awareness.
WHO Updates Essential Medicines List (2025)
Why in News: WHO released the 24th Model List of Essential Medicines (EML) and 10th Essential Medicines for Children (EMLc) in 2025.
Context: Updates reflect new treatments for cancer, diabetes, obesity, cystic fibrosis, psoriasis, haemophilia, and blood disorders.
Significance
- Launched in 1977 to identify medicines meeting priority health needs.
- Guides 150+ countries in procurement, insurance coverage & health policy.
- Ensures access to effective, safe, and affordable medicines.
- Current lists: 523 medicines (adults), 374 (children).
New Additions & Revisions
- 59 applications reviewed → 20 new medicines in EML, 15 in EMLc.
- 7 existing medicines: new indications.
- Focus on cancer, diabetes, obesity, blood disorders.
Cancer Medicines
- Cancer = ~10 million deaths annually.
- Only drugs with proven survival benefit (4–6 months) included.
- Additions: PD-1/PD-L1 immune checkpoint inhibitors (pembrolizumab, atezolizumab, cemiplimab).
- Access strategies: dose optimisation, affordability in resource-poor settings.
Diabetes & Obesity Medicines
- Diabetes: affects 800+ million; Obesity: > 1 billion people worldwide.
- Additions: GLP-1 receptor agonists (semaglutide, dulaglutide, liraglutide) & dual GLP-1/GIP agonist tirzepatide.
- Benefits: better blood sugar control, reduced cardio-renal risks, aid in weight loss, lower mortality in type 2 diabetes with comorbidities.
- Challenge: high cost, limited access → call for generic competition & integration into primary care.
Challenges in Access
- High out-of-pocket expenditure on essential medicines, especially NCDs.
WHO stresses:
- Political will.
- Multisectoral cooperation.
- People-centred health programmes.
- Ongoing monitoring of pricing & availability.
Expert Committee Process
- 25th WHO Expert Committee met in Geneva (May 2025).
- Evaluated medicines on effectiveness, safety, cost, cost-effectiveness.
- Reviewed AWaRe antibiotic classification.
- Updates every two years to remain aligned with global health priorities.
India’s First Hydrogen-Powered Rail Coach
Why in News: Union Railway Minister announced successful testing of India’s first hydrogen-powered coach at the Integral Coach Factory (ICF), Chennai. To be deployed on Jind–Sonipat (89 km) route, Haryana.
Design & Development
- Developed by Research Design & Standards Organisation (RDSO).
- Conversion of two 1600 HP diesel power cars into hydrogen fuel cell traction system.
- Hydrogen storage & fuelling facility set up at Jind, Haryana (capacity: 3,000 kg hydrogen).
Working Principle
- Hydrogen fuel cell: Hydrogen + Oxygen → Electricity + Water + Heat (electrochemical reaction).
- Regenerative braking: captures kinetic energy during deceleration → recharges onboard batteries.
Safety Features
- Equipped with pressure relief valves, leak & flame detectors, temperature sensors, ventilation systems.
- Independent safety audit by TÜV-SÜD (Germany).
- Compliance with PESO (Petroleum Explosives Safety Organisation) standards.
Significance
- Hydrogen is a clean fuel → reduces dependence on fossil fuels.
- Supports India’s Net-Zero goals.
- Hydrogen-powered trains already tested in Germany, France, Sweden, China.
Key Initiatives
Hydrogen for Heritage
- Indian Railways’ plan: 35 hydrogen trains on heritage & hill routes to cut diesel use and emissions.
National Green Hydrogen Mission (Launched: Jan 4, 2022)
- Target: 5 MMT of Green Hydrogen by 2030.
- Aims:
- Make India a global hub for production, use & export of green hydrogen.
- Reduce fossil fuel imports.
- Promote indigenous manufacturing of electrolysers.
- Create large-scale employment opportunities.
India Reaffirms Commitment to WTO-Centred Fair Trade System
Why in News: At the SCO Trade Ministers’ meeting, India reiterated its support for an open, fair, inclusive, and non-discriminatory multilateral trading system with the World Trade Organisation (WTO) at its core.
About WTO
- HQ: Geneva, Switzerland.
- Established: 1995 (post Marrakesh Agreement).
- Successor: General Agreement on Tariffs and Trade (GATT).
- Members: 166 (India member since 1995).
Core Principles:
- Trade without discrimination (MFN & National Treatment).
- Free trade through negotiation.
- Promoting fair competition.
- Predictability and transparency.
Key Issues Facing WTO
Public Stockholding (PSH):
- Government programmes (e.g., India’s MSP regime) considered trade-distorting.
- Debate on food security vs. market distortion.
Special & Differential Treatment (S&DT):
- Grants developing & LDCs favourable treatment.
- Developed nations seek to phase out.
Dispute Settlement Mechanism:
- WTO Appellate Body non-functional since 2019 (US blocked appointments).
- Weakens enforcement of trade rules.
Geopolitical Shifts:
- US tariff policies, Russia–Ukraine war affecting global trade.
New Trade Concerns:
- Digital trade: data flows, taxation of digital services.
- Climate measures: EU’s Carbon Border Adjustment Mechanism (CBAM).
- Data privacy & environmental sustainability.
